This episode I describe how we see, meaning how our eyes focus,
convert light information into electricity the rest of the brain can
understand and how our brain creates the incredible thing we
experience as “sight”. I also describe how we can train and support
our visual system to improve at any age. I describe more than a dozen
protocols to support depth perception, offset near-sightedness,
improve mood, sleep, and our ability to focus (both visual focus and
our mental focus generally). I also explain how to use eyesight to
improve our levels of alertness and why visual hallucinations, lazy
eyes and colorblindness occur. I also describe various compounds that
may assist in supporting visual health and possibly improve our
vision. Many simple, zero-cost protocols and a lot of scientific
mechanisms are covered in this episode in clear language anyone can
understand-- it is for anyone that values their brain and their
eyesight, whether young, adult-age or advanced age.
- Introduction
- Protocol: Concurrent Training For Endurance, Strength, Hypertrophy
- The Senses, Vision, Seeing & What We Should All Do To See Better
- Our Eyes: What They Really Do, & How They Work
- Converting Light Into Electricity Language: Photoreceptors, Retinal Ganglion Cells
- We Don’t See Anything Directly: It Is All A Comparison Of Reflected Light
- Dogs, Cats, Snakes, Squirrels, Shrimps, Diving Birds, & You(r View Of The World)
- Everything You See Is A Best Guess, Blind Spots
- Depth Perception
- Subconscious Vision: Light, Mood, Metabolism, Dopamine; Frog’s Skin In Your Eyes
- Blue-Yellow Light, Sunlight; & Protocol 1 For Better Biology & Psychology
- Protocol 2: Prevent & Offset Near-Sightedness (Myopia): Outdoors 2 Hours Per Day
- Improving Focus: Visual & Mental; Accommodation, Your Pupils & Your Bendy Lens
- Protocol 3: Distance Viewing For 20min For Every 90 Minutes of “Close Viewing”
- Protocol 4: Self-Generated Optic Flow; Move Yourself Through Space Daily
- Protocol 5: Be More Alert; Eyelids, Eye Size, Chin Position, Looking Up Versus Down
- Protocol 6: Sleep In A Very Dark Room To Prevent Myopia (Nearsightedness)
- Color Vision, Colorblindness, Use Magentas Not Reds
- Protocol 7: Keeping Your Vision Sharp With Distance Viewing Every Day
- Protocol 8: Smooth Pursuit
- Protocol 9: Near-Far Visual Training 2-3 Minutes 3-4 Times a Week
- Protocol 10: Red Light, Emerging Protocol To Improve Photoreceptors & Vision
- Dry Eyes; Blinking, Protocol 11
- Lazy Eye, Binocular Vision, Amblyopia; Triggering Rapid Brain Plasticity; Protocol 12
- Protocol 12: Determine Your Dominant Eye; Near-Far Training
- Visual Hallucinations: The Consequence of An Under-Active Visual Brain
- Protocol 13: Snellen Chart: A Simple, Cost-Free Way To Test & Maintain Vision
- Vitamin A, Lutein, Idebenone, Zeaxanthine, Astaxanthin, Blood Flow
- Summary of Protocols, Vital Point About Blood & Oxygen For Vision
- Episode Length, Captions, Zero-Cost Support, Instagram, Searching Topics
-- Welcome to the Huberman Lab Podcast, where we discuss science and
science-based tools for everyday life. [gentle music] I'm Andrew
Huberman, and I'm a professor of neurobiology and ophthalmology at
Stanford School of Medicine. This podcast is separate from my teaching
and research roles at Stanford. It is, however, part of my desire and
effort to bring zero cost to consumer information about science and
science-related tools to the general public. In keeping with that
theme, I'd like to thank the sponsors of today's podcast. Our first
sponsor is Roka. Founded by two All-American swimmers from Stanford,
Roka eyeglasses and sunglasses have really been designed with the
utmost care and the utmost attention to the science of optics and the
visual system. So one of the things I like so much about Roka
eyeglasses and sunglasses is that they're extremely lightweight. If
you get sweaty, so for instance, if you wear them while running, or
walking, or hiking, they don't slip off. And with the sunglasses, when
you're outdoors, if there's cloud cover, or if there's shadows, or if
the day gets brighter or dimmer, you can still see your surroundings
perfectly well. And that's because the designers at Roka really
understand the way the visual system works how it habituates, how it
adapts. You don't need to understand the science behind all that, but
they do, and as a consequence the eyeglasses perform extremely well
under all conditions, whether or not that's indoors or outdoors. So
they put a ton of science and purpose into the design. They also
happen to look really good. They have a really nice aesthetic. A lot
of, as you know, performance active wear eyeglasses look rather
ridiculous, but the Roka glasses, I think, have a very nice aesthetic
to them that you can wear anywhere. If you'd like to check out Roka
glasses, you can go to Roka, that's roka.com and enter the code
Huberman at checkout, and you'll get 20% off your first order. That's
Roka, R-O-K-A .com and enter the code Huberman at checkout for 20% off
your order. Today's podcast is also brought to us by Inside Tracker.
Inside Tracker is a personalized nutrition platform that analyzes data
from your blood and DNA to help you better understand your body and
reach your health goals. I'm a big believer in getting regular blood
work done for the simple reason that many of the factors that impact
our immediate and longterm health can only be analyzed from a blood
test. And now, with the advent of modern DNA tests, we can also get
insight into our specific DNA makeup and how that influences our
lifestyle choices and our health status. The problem with a lot of
blood tests is that you get a lot of information back, but you don't
always know what to do with that information. With Inside Tracker,
they have a very easy to use, personalized dashboard platform that
informs you what sorts of lifestyle, nutrition, exercise, changes you
might want to make, according to the levels of particular metabolic
factors, hormone factors, et cetera, in your blood and DNA. So it
makes everything very simple, both in terms of where you're at health-
wise and what you should or could do, in order to improve your health,
something I do believe most everybody would like to do. With Inside
Tracker, it makes all that very easy. They also have something called
the inner age test. This is a test that shows you what your biological
age and compares to that, of course, to your chronological age. And,
of course, your biological age is really what you want to know,
because it's a predictor of how long you're going to live and the
quality of your life. If you'd like to try Inside Tracker, you can
visit insidetracker.com/huberman. And if you do that, you'll get 25%
off any of Inside Tracker's plans, just use the code Huberman at
checkout. Today's episode is also brought to us by Helix Sleep. Helix
Sleep makes mattresses and pillows that are ideally suited to your
sleep needs. Everybody needs something different in terms of what to
sleep on. Some people like a hard mattress. Some people like a soft
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With Helix Sleep, you go to their website, you take a very brief two-
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and Helix understands that, and that's built into the design of their
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If you'd like to try a Helix Sleep mattress, you can go to
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You'll get a 10-year warranty on that mattress, and you get to try it
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and two free pillows.
We are now beginning a new topic for the next four to five episodes of
the Huberman Lab Podcast. Before we move into that, I want to just
briefly touch on a couple questions that I got from the last episode,
which was related to the science of endurance training. I described
the four kinds of endurance training. We posted protocols of the
specific four kinds of endurance training at hubermanlab.com. Just go
to that episode, you can see the download, it's a zero-cost PDF. I got
a lot of questions about what's called concurrent training, which is
how to program endurance training if you are also interested in
strength and hypertrophy training. Or how to incorporate strength and
hypertrophy training, which was in the previous episode, with
endurance training. This can all be made very simple. Ask yourself,
what are you trying to emphasize, and then emphasize that for a 10 to
12 week cycle. So if you're mostly interested in endurance, I would
say use a three to two ratio, maybe get three endurance training
workouts per week, maybe four, and two strength and hypertrophy
workouts. If you're mainly focusing on strength and hypertrophy, get
three or four workouts for strength and hypertrophy and do two
endurance workouts. Start with the minimum number of sets that's
required to get the result that you want. So if you're not accustomed
to doing endurance work, you would start with the minimum number
that's listed on that protocol. So if it says three to five sets, you
would start with three, maybe even just two, and then work your way up
by adding sets each week. I do suggest that people get at least one
complete rest day per week. And although I know a lot of people don't
like that, I benefit from that. I actually benefit from having two
complete rest days each week. I just continue to make progress that
way, whether or not it's for strength and hypertrophy or for
endurance. I am a big believer in rest days, other people are not. And
those could be active rest days, hiking, relaxing, et cetera. After a
10 to 12 week cycle, then I also suggest taking anywhere from five to
seven days completely off. You can still enjoy life and do things, I
know for you addicted exercisers that you're going to loathe to do
that, but that's one way to stay injury free, keep your joints and
tissues healthy over time, and continue to make progress. If you don't
want to do that week off, don't do it. None of this is holy. None of
it is a strict prescriptive. Just ask yourself, what are you going to
emphasize and emphasize that, in terms of the total volume of workouts
that you do, and work up incrementally, and then move into another
cycle. That's what I suggest. So go to hubermanlab.com, you can get
the protocol there. We are now going to move into a new topic
unrelated to physical performance.
Starting with this episode and for the next four to five episodes, we
are going to talk all about the senses. That's sight, eyesight,
hearing, touch, taste, smell, and we're also going to talk about this
critical sense that we call interoception, or our sense of our
internal real estate. Now, the reason that we are talking about the
senses is because if you understand how the senses are perceived, what
they're about, what the underlying cells and connections are about,
you will be in a terrific position to understand the month's topic
that follows, which is all about mental health. Now, I want to
emphasize that if you're somebody who doesn't have any trouble seeing,
hearing, tasting, smelling and has an excellent sense of
interoception, I do believe that these episodes will still be very
relevant to you, because they have everything to do with how you move
through the world, how you make sense of information, and how you
organize your thoughts and your emotions. I also want to emphasize
that we're going to cover a lot of practical tools. So today's episode
is going to be all about vision and eyesight, a topic that's very near
and dear to my heart, because it's the one that I've been focusing on
for well over 25 years of my career. But we're not just going to get
into the mechanistic details about how light is converted into
electrical potentials and things like that. We are going to talk about
practical tools that you can and should use to help maintain the
health of your visual system and your eyesight. Very often, young
people will say, what should I do? You know, you're always talking
about, you know, neuroplasticity and how it tapers off over time, but
I'm a young person, what should I do? You should absolutely train and
support your eyesight. In fact, if you're a young person and you see
perfectly, or you feel as if you see the world perfectly, you are in
the best position to bolster, to reinforce that visual system, so that
you don't lose your vision as you age. In addition, you can leverage
your visual system for better mental and physical performance, and
we're going to talk about that. If you're somebody who suffers from a
clinical disorder of vision, you have trouble seeing, or if you need
corrective lenses in order to see, this episode is definitely for you.
And while of course I can't make clinical diagnoses, I can't have a
one-to-one conversation with any of you in this format, nor am I a
clinician, I'm a scientist, not a physician. I did consult with our
chair of ophthalmology, Dr. Jeffrey Goldberg at Stanford University
School of Medicine, as well as several other people to really vet the
information and make sure that the protocols that I'm describing are
consistent with the clinical literature. If you have a severe eye
problem, you should be working with a really good ophthalmologist
and/or optometrist, but certainly an an ophthalmologist who's a
medical doctor. But I do believe that the information that we're going
to discuss today is going to be relevant to everybody and will set the
stage for the month on mental health and mental performance. So, let's
get started.
When we hear the word vision, we most often think about eyesight, or
our ability to perceive shapes, and objects, and faces, and colors.
And indeed, vision involves eyesight, our ability to see shapes, and
objects, and faces, and colors, and so forth. However, our eyes are
responsible for much more than that, including our mood, our level of
alertness, and all of that is included in what we call vision. So I
just want to take about three, maybe four minutes, and talk about how
the visual system works, how it's built, and how you are able to so-
called see things around you. I also want to describe the ways in
which your eyes and your visual system impact your mood and your level
of alertness. And then, we are going to get right into some protocols,
some specific things that each and all of you should do if you want to
enhance your vision and maintain your vision as you get older. And
again, if you're a 15-year-old or a 12-year-old, this episode is
especially for you, because your nervous system is far more plastic
than mine is. It's much more amenable to change, so you can really
build a very strong visual system. And in doing that, and if you adopt
specific behaviors at any age of light viewing at particular times and
particular ways, then you can build an emotional system that's also
reinforced by your visual system. So, let's talk about vision. What is
vision? Well, vision starts with the eyes. We have no what's called
extraocular light perception. While it feels good to have light on our
skin, while it feels good to be outside in the sunlight for most
people, the only way that light information can get to the cells of
your body is through these two little goodies on the front of your
face. And for those of you listening, I'm just pointing to my eyes. As
many of you have heard me say before, on this and other podcasts, your
eyes, in particular, your neural retinas are part of your central
nervous system. They are part of your brain. They're the only part of
your brain that sits outside the cranial vault. In other words, you
have two pieces of your brain that deliberately got squeezed out of
the skull during development and placed in these things we call eye
sockets. There's a genetic program for the specific purpose of making
sure that three little layers of neurons, nerve cells, got squeezed
out and form what are called your neural retinas. Now, the eyes have a
lot of other goodies in them that are very important, and those are
the goodies that we're going to focus on a lot today. There's a lens
to focus light, precisely to the retina. If you're somebody who
requires eyeglasses or contacts, chances are, you don't do that
correctly, and so, that's why you use other lenses, like eyeglasses or
contacts. There are also other pieces of the eye that are designed to
keep the eye lubricated. You also have these things that we call
eyelashes. Most people don't know this, but eyelashes are there to
trigger the blink reflex if a piece of dust or something gets in front
of your eye. It's a beautiful adaptation of nature. They aren't just
aesthetically nice. Costello happens to have very long eyelashes. He
gets compliments about this all the time. Maybe you have long
eyelashes. I don't have particularly long eyelashes. But the eyelashes
are there, so that if a piece of dust or something starts to head
towards the cornea, the eye blinks very, very fast. It's the fastest
reflex you own is your eye blink reflex. We also have these things
called eyelids. Now, eyelids might seem like the most boring topic of
all, but they are incredibly fascinating. Today, we're going to talk
about how you can actually use your visual system to increase your
levels of alertness based on the neural circuits that link your
brainstem with your eyelids. And no, we are not going to have a
blinking contest, because I would win and you would lose, and that
wouldn't be fun for you. So, let's talk about what the eyes do for
vision.
Basically, the entire job of the eyes is to collect light information
and send it off to the rest of the brain, in a form that the brain can
understand. Remember, no light actually gets in past those neural
retinas. It gets to the neural retina, and we have specific cells in
the eye called photoreceptors. They come in two different types, rods
and cones. Cones are mainly responsible for daytime vision, and the
rods are mainly responsible for vision at night or under low light
conditions, generally speaking. So basically what happens is if your
eyelids are open, light comes into the eye, the lens focuses that
light, light is also just called photons, light energy, onto the
retina. These photoreceptors, the rods and cones, have chemical
reactions inside them that involve things like vitamin A and that
chemical reaction converts the light into electricity. Now, that might
seem incredibly abstract, but the way to think about this is very
similar to, for instance, you have touch receptors on your skin and
when you press on those touch receptors, they convert pressure,
physical pressure, into electrical information and those neurons send
it up to your spinal cord and brain, and you can register that
somebody or you are touching the top of your hand, as I'm doing now.
With the eyes and the retina, it's just that light gets converted into
electrical information. Within the eye, within the retina, there are
then a series of stages of processing, and that information eventually
gets sent into the brain by a very specific class of neurons. I would
like you to know the names of these neurons. They're called retinal
ganglion cells. So the only thing you need to know about the
neuroscience of the eye at this point are that there are rods and
cones. The cones are involved in bright daytime vision and rods are
involved in more dusk or nighttime vision. And you've got these cells
called retinal ganglion cells that send the information off to the
rest of the brain. Now, here's what's incredible. I just want you to
ponder this for a second. This still blows my mind. Everything you see
around you, you're not actually seeing those objects directly. What
you're doing is you're making a best guess about what's there based on
the pattern of electricity that arrives in your brain. Now, that might
just seem totally wild and hard to wrap your head around, but think
about it this way, because this is the way it actually works.
Let's take an example of a color, like green or blue. You have cones
in your eye that respond best to the wavelength of light that is
reflected off, say, a green apple. So, you don't actually see the
green apple. What you see is the light bouncing off that green apple,
and it goes into your eye, and you see it and perceive it as round and
green, but not because you see anything green. No green light arrives
in your brain. What happens is your brain actually compares the amount
of green reflection coming off that apple to the amount of red and
blue around it. Well, you might say, well, the green apple is sitting
on a brown table or a white surface. Well, then, it will appear very
green. Because the amount of wavelength of light for green is very
high, and the amount for red is very low, and so, it looks very green,
okay? So, we don't actually see anything directly. What the brain is
receiving is a series of signals, electrical signals, and it's
comparing electrical signals, in order to come up with what we call
these perceptions. Like I see something green, a green apple, or I see
red. Let me give you a slightly different example. If you were to play
a key on the piano, let's say you play, I'm not a musician, but I'm
going to, so hopefully I won't get this too incorrectly but let's say
you have like E sharp, and maybe it's like ding, ding, ding, ding,
ding. If the brain gets that signal, it doesn't actually know E that's
what, it doesn't recognize it until you were to play another key next
to it, dun, dun, dun, dun, and what it does, it does the math, it does
the subtraction, and it compares those two. So when we see something
green, or we see something red, or we see something blue, we're not
actually seeing it directly. The brain is making a guess about how
green or red or blue that thing is by comparing what's around it,
okay? And if that seems hard to wrap your head around, don't worry,
because we will explain it in more depth going forward. But I really
want people to understand this, that vision, eyesight, is not looking
at things directly, and that information getting directly into your
brain, it is translated. Light information is transformed into
electrical signals that your visual system exquisitely understands.
Now, what does this mean? Why should you care about this? Well, if you
have a dog like I do, or a cat, they are not colorblind, but they lack
the cones that respond to red, meaning long wavelength light.
So what does that mean? That means that when they see green, it's
different than the green you see. Not because that apple is invisible
to them, but because they aren't able to compare it to red, and you
are. As a consequence, when they look at a green lawn, it looks more
brownish or orange to them. When you wear a red shirt in front of your
dog or cat, if you see a stop sign and they see a stop sign, they see
orangish-brown, and you see red. presuming that you are a trichromat,
meaning you have three-color vision. So, this is all to say that every
animal sees the world differently, depending on whether or not they
have one or two or three of these different cones, the red, blue, or
green cones. If you are a mantis shrimp of all things, you see
hundreds of colors that human beings can't see, okay? Many things
animals see into visual ranges that you and I can't see in. So for
instance, a pit viper senses heat emissions, it literally sees the
heat coming off of you or of an animal that they want to eat. If you
are a ground squirrel, you can see ultraviolet light. This is going to
sound kind of weird, but ground squirrels actually signal one another
by standing up outside and shining sunlight off each other's stomachs
to each other, signaling at a distance, just like, you know, you could
signal somebody with a mirror in sunlight at distance. There are
species of primates, this isn't very pleasant to think about, that
urinate on their hands, and then wipe it all over their stomach. and
then use that sunlight to reflect different signals to each other. I
don't know what they're saying. We always assume it's something cute
and nice, but maybe they're insulting each other. So this actually
gets right down to the heart of these bigger questions, like
consciousness, what do we see? What's out there? How much of life is
really accessible to us? And I could go on and on, you know, this used
to be kind of an obsession of mine when I was coming up in the field
of visual neuroscience to understand how different animals see the
world compared to us. You know, I'll give one more example, a diving
bird, you know, a bird that flies over the ocean. It has an incredible
task. It has to both view the horizon, and it has to view schools of
fish, and then, it has to make a trajectory down into the water and
grab one of those fish to eat. And the water has what's called a
refractory index. It actually shifts like a prism, the impression or
the perception of where that fish is, right? If the bird sees the fish
right below it, it has to know, it has to adjust its diving trajectory
just right, because it knows that that fish actually isn't where it
sees it. It's probably a few inches ahead or to the side of that,
because of the way that water diverts the image. If you've ever
dropped a coin to the bottom of a pool, if you go straight down
looking at that location. If you were to look from the top of the
pool, and you dive straight down with your eyes closed, you will miss,
because the water refracts, it shifts the visual image. Well, diving
birds have an arrangement of these retinal cells that communicate to
the brain that's both a streak to view the horizon, 'cause they need
to know where they are relative to the horizon, and they have a pupil
like we do on the bottom of their eye, so that they can make very
accurate dive and attacks on these schools of fish, and catch fish,
and eat those fish. We just have pupils in the middle of our eyes. So
there's a ton about the optics of the eye, and the way that it
communicates with the brain that allows us to see. We could spend
hours talking about this, but what I'd like to embed in your mind is
that what you experience in the outside world is bottlenecked, it's
limited by which wavelengths, which colors if you will, of light that
you can see. That your brain is coming up with a best guess about
what's there. It doesn't actually know what's there. And that your
vision is distinctly different from say, the vision of a dog or from
the vision of somebody who's a dichromat, meaning they don't have a
red cone. A lot of people, in particular about 1 in 80 males, lacks a
red cone and therefore, sees the world much the same way that Costello
does. Although, he sees it from just much lower toward the ground. So,
that's what I'd like you to understand about the way the eye
communicates with the brain. I would also like you to understand that
the brain itself is making these guesses and that those guesses are
largely right.
How do I know that? Well, they're right because when you reach out to
grab a glass, most of the time you grab the glass, and you don't miss,
right? Most of the time, when you make judgments about the world
around you, based on your visual impression of them, it allows you to
move functionally through the world. But let me give you some examples
of where this guessing is happening right now. And it's so incredible
that, to this day, this still blows my mind. Cover one eye with one
hand. If you're driving, maybe don't do this. If you're viewing the
world around you, presumably you can see everything that's out there.
I could do this with one eye or the other eye. You probably see better
out of one or the other, and we'll talk about that. You have a giant
blind spot in the middle of your visual field. It's called your blind
spot. It is the spot in which the connections, the wires, from all
those retinal ganglion cells exit the back of the eye and head off
toward the brain. In other words, you are blind for a huge spot of
your central vision. The part of your vision that's highest acuity,
highest detail, and yet, you don't see that ever. You cover one eye,
and you see perfectly fine. And it's not just because your eye is
moving around really quickly. Your brain is guessing what's in that
spot, which is absolutely incredible, and so, you don't see that blind
spot. This is happening all the time. Now, when you have two eyes
open, the way that your eyes are positioned in your head and the way
they view the world is such that they fill in each other's blind
spots, so it's pretty convenient. But if you cover one eye, that's
impossible, and yet, you still see the world as complete. So the brain
is doing these incredible things. It's also creating depth, a sense of
depth.
Even though what arrives from the retina is essentially a readout of a
two-dimensional, flat image, so it can sense depth. How do you know
depth? Well, this is very simple. Things that are closer to you tend
to be larger than things that are far away. Things that are closer to
you tend to look like they're moving faster. If you've ever been in a
train and you look to your side, the rungs on a fence, or the train
tracks going by you, look like they're going very fast. If you look
off in the distance, they look like they're moving very slowly. And
there are differences between what's close to you and what's further
away. So, a little house on the horizon, you don't look at it and say,
oh, that must be a tiny, little house. You have some prior knowledge
that things further away are smaller. So that's the main way that you
do that. And you compare the location, at which information about
light lands on the two eyes. So your eyes are slightly offset from one
another. So that, for instance, if I look at you, if you were standing
right in front of me right now, and I were to look at you, the image
of your face, the light bouncing off your face to be more precise,
lands on one eye in a slightly different location than it does in the
other eye, and then the brain does math. It basically does the
equivalent of geometry and trigonometry, and essentially figures out
how far away you are from me, which is just incredible. So the brain
does all this very, very fast, and the brain uses about 40 to 50% of
its total real estate for vision. That's how important vision is. Now,
for those of you that are blind, or low vision, or no vision, that
real estate in the brain will be taken over by neurons that control
sense of touch and a sense of hearing, and your, indeed, hearing and
touch are much better, higher acuity, and faster in blind people. But
for most of you, who I presume are sighted, this is how it works. So,
that's kind of vision from eye to brain in a nutshell. There are a
bunch of different stations in the brain that do different things.
That's eyesight. Now, I want to talk about the other aspect of vision,
which is the stuff that you don't perceive, the subconscious stuff.
And then, we'll transition directly into how you can use light and
eyesight to control this other stuff because it's very important and
that other stuff is mood, sleep, and appetite. And there are ways in
which you can use the same protocols that I will describe, in order to
preserve and even enhance your vision, your ability to see things and
consciously perceive them. So the protocols we will describe have a
lot of carry over to both conscious eyesight and to these subconscious
aspects of vision. And I just want you to understand a little bit more
about the science of seeing, of eyesight and vision, and then all the
protocols will make perfect sense. So as amazing as eyesight is, it
actually did not evolve for us to see shapes and colors and motion and
form. The most ancient cells in our eyes, and the reason we have eyes,
is to communicate information about time of day to the rest of the
brain and body. Remember, there's no extraocular photo reception.
There's no way for light information to get to all the cells of your
body, but every cell in your body needs to know if it's night or day.
And I talked a little bit about this on the, in the episodes on sleep,
and this episode is not about sleep. But I want to emphasize that
there is a particular category of retinal ganglion cell, remember the
neurons that connect the retina to the brain, that is involved in a
special kind of vision that has nothing to do with conscious
perception of what's around you, and it's happening right now, it's
happening all the time. These are so-called melanopsin retinal
ganglion cells, named after the opsin that they contain within them.
They are essentially photoreceptors, remember before I said there are
photoreceptors and then these ganglion cells? Well, these melanopsin
cells, as the name suggests, melanopsin, have their own photoreceptor
built inside them. The opsin that they contain is actually very
similar to the melanopsin that is present in the skin of some
amphibians and that causes those amphibians to change their skin color
in different light conditions. So you have, believe it or not, a
little bit of frog skin in your eye, so to speak. Okay, not exactly,
but you essentially have the equivalent of what frogs have on their
skin in your eye. If you are low vision or no vision, as long as you
have retinas, it's very likely you still have these cells, even though
you can't see or you don't see well. These cells, retinal ganglion
cells, communicate to areas of the brain when particular qualities of
light are present in your environment and signal to the brain,
therefore, that it's early day or late in the day. These melanopsin
ganglion cells are sometimes also called intrinsically photosensitive
cells because they behave like photoreceptors. What do these cells
respond to, and why should you care about them? Well, you should care
about them, because they regulate when you'll get sleepy, when you'll
feel awake, how fast your metabolism is, excuse me, your blood sugar
levels, your dopamine levels, and your pain threshold. There are other
factors that impact those things, but they are one of the, if not the
most powerful determinant, of those other things like mood and pain
threshold, sleepiness, wakefulness, et cetera. These melanopsin
ganglion cells have been shown by the Nitz Group, N-I-T-Z, up at
University of Washington, and by Samer Hattar's lab and David Burson's
lab, and a number of other people's labs, Satchin Panda, Prevencio, et
cetera, a number of excellent labs in neuroscience to set the
circadian clock and to respond best to the contrast between blue and
yellow light of the sort that lands on the cells when you view the
sun, when it's a so-called low solar angle, when it's low in the sky,
either in the morning or in the evening, what does all this mean?
It means, and here's the first protocol, and you've probably heard me
say this before, but is appropriate to this episode to say it again.
If you are not viewing the sun, sunlight, even through cloud cover,
for two to 10 minutes in the early part of the day, when the sun is
still low in the sky and doing the same thing again in the evening,
you are severely disrupting your sleep rhythms, your mood, your
hormones, your metabolism, your pain threshold, and many other
factors, including your ability to learn and remember information. The
most central and important aspect of our biology, and perhaps our
psychology as well, is to anchor ourselves in time, to know when we
exist. Okay, it sounds a little bit abstract and philosophical, but
it's not. And we don't know time as a real thing because of watches
and clocks. We know time at a biological level, based on where the sun
is and where, which of course is where we are relative to the sun,
because the earth is spinning around. Now, what does this mean for a
protocol? It means, see, get that light in your eyes early in the day,
and anytime you want to be awake. So try and get as much sunlight in
your eyes during the day as you safely can. We'll talk about eye
safety this episode in depth. And the blue light and the contrast of
that blue yellow, remember we don't see blue, this is all
subconscious. This is blue reflections coming off of sunlight. Blue
light, we've been told is so terrible for us, it is absolutely
essential and wonderful for waking up the brain, for triggering all
sorts of positive biological reactions, but it needs to be viewed
early in the day. If you can't see sunlight, because it's the thick
cloud cover of say a, you know, you're in the UK and it's winter, then
artificial lights, especially blue lights, would be very beneficial to
you. We need a lot of this light and its contrast with yellow, in
order to trigger these melanopsin cells, which will then trigger your
circadian clock, which sits above the roof of your mouth, which will
signal every cell in your body, including temperature, rhythms, et
cetera. So first things first, your visual system was not for seeing
faces, motion, et cetera. The most ancient cells in your eye, which
are there right now as we speak, are there to inform your body and
brain about time of day, so you want to get that bright light early in
the day. Absolutely essential, two to 10 minutes, you can download the
light meter app if you want to measure lux. When we, when I explained
how to do that in earlier episodes it got a little convoluted, get
that two to 10 minutes, ideally without sunglasses. Now, here's
another reason to do this, and I've never spoken about this before on
any podcast, which is that there have been several studies now in
thousands of subjects, exploring what can be done to prevent myopia,
nearsightedness, and other visual defects.
And it turns out, in a series of large clinical trials, the conclusion
has emerged that getting two hours a day of outdoor time without
sunglasses, blue light, this blue light that everyone has demonized,
getting that sunlight during the day for two hours, even if you're
reading other things, and doing other things outside, has a
significant effect on reducing the probability that you will get
myopia, nearsightedness. Now, whether or not that's also due to the
fact that myopia can be caused by viewing things up close to too much.
So if you're indoors, we tend to be looking at things more closely,
right? Unless you have a very large house with walls that are very far
away from you, but the effect does seem to be directly related to
getting sunlight, and not just to the distance that you're viewing.
I'm going to describe this study just briefly, but this is a second
protocol. So we have one protocol about getting sunlight to set your
circadian clocks, meaning wake you up, establish your sleep, will
occur about 12 to 16 hours later, that's all in the sleep episode. But
also to enhance your mood, to enhance your metabolism, to optimize
your hormone levels, and to optimize learning and dopamine levels,
this feel good neuromodulator that's essential to not getting
depressed, et cetera. But now's the second protocol, which is ideally,
and this includes children, as long as they're not very small infants,
ideally, we're all getting two hours of outdoor time, even if there's
cloud cover. Remember, we evolved mostly under outdoor conditions, not
indoor conditions, and no artificial blue light will not replace this
aspect of your visual system and offsetting myopia. So I just want to
briefly describe this study, because it's a very important one, and I
don't think it's discussed often enough. There are many studies
exploring this, but one of the ones I liked the most, looked at 693
students, and a subset of them were encouraged to spend 11 hours a
week outdoors. Okay, so most kids are in school five days a week or
so, so they're spending 11 hours a week outdoors. They are sometimes
reading outdoors. They're not always just playing outdoors, they might
be reading books, et cetera. They used eight different schools. And
the reason they did the study, I probably should have mentioned, is
that myopia, nearsightedness, is a global epidemic. At least, that's
how it was referred to in the study. I don't know who decides what's
an epidemic or not. I think there are thresholds for that. This paper
published in the journal Ophthalmology in 2018 described the fact that
being outdoors for two hours a day could significantly reduce the
probability that these children would develop nearsightedness. And it
turns out based on other studies, that adults who spend two hours a
day outside, that would be reading outside, talking outside. No, it
does not include light coming through the windshield of your car, I'll
explain why in a few moments, offset the formation of myopia. Now,
myopia, or nearsightedness, has to do with the way that the lens
focuses light onto the retina. I don't want to get into a long
description of this now, but basically the lens has bring light to the
retina, not in front of it, not behind it. If it brings light to a
position in front of the retina, then you won't see clearly, you will
need corrective lenses. If it brings light directly to the retina,
then you will see clearly, that should be intuitive why that makes,
why it makes sense. So you might say, well, why would being outside,
getting this blue light or this blue-yellow contrast from sunlight
actually offset myopia? Well, it probably, and I want to emphasize
probably has to do with the fact that these melanopsin ganglion cells,
these intrinsically photosensitive ganglion cells, are not just
responsible for sleep, and talking to your circadian clock, and that
sort of thing, they also make connections within the retina. They
connect to things like, this is for the aficionados, the ciliary body,
the iris, the muscles and the structures within the eye that actually
move the lens and allow you to adjust your vision to things up close
or far away. And in doing so, they increase or improve the health of
the little tiny muscles within the eye that move the lens. And they
probably, again, this needs a little bit more work, in order to really
tamp down the mechanism. They're probably also involved in bringing
growth factors and blood supply to the muscles and to the neurons that
are responsible for this focusing mechanism within the eye. So
remember, your eye is an optical device. You were born with lenses,
you don't have to use glasses, or maybe you do because you have lenses
in your eyes and those lenses need to move. It's not a rigid lens,
like a glass lens. It's a dynamic lens, and it has little muscles that
pull on it, and squeeze it, and make it thicker or thinner, as you
look at things close and far away, and I'll describe how that works in
a moment. These melanopsin cells and their activation by sunlight,
completely subconsciously, unaware, you're unaware of this, promote
the health of this system within the eye and allow you to offset the
myopia, nearsightedness. In other words, getting outside for two hours
a day, each day, on average, even if there's cloud cover, without
sunglasses on, will allow you to offset the formation of myopia. Now,
you might still form myopia if you have certain structural features or
a genetic basis for that, we will talk about things that you can do as
well. But for everybody, we should be doing this. And that might seem
like a lot, but this is the way that your visual system works. Staying
indoors, just getting artificial light, and looking at things up close
leads to visual defects. Okay, it's a form of kind of like visual
obesity, right? The posture of your visual system, if you will, is
going to be unhealthy if you're just indoors and you're not getting
sunlight early in the day and for at least two hours per day. I want
to talk a little bit more about how our eyes adjust to things that are
close to us or far away. This is an absolutely brilliant consequence
of our nature and our design. And whenever I say nature and design,
people always ask me, you know, what are you really trying to say? Are
you trying to talk about creators? Are you talking about intelligent
design? Look, I want to be very frank with you. I wasn't consulted at
the design phase, and neither were you. And so, that is all very
interesting, but it's not the topic of this discussion.
What is clear and what is the topic of this discussion is that the eye
can dynamically adjust where light lands by moving the lens and
changing the shape of the lens in your eye, through a process called
accommodation. And if you understand this process of accommodation,
you not only can enhance the health of your eyes in the immediate and
long-term, but you also can work better. You'll be able to focus
better on physical and mental work. You will be able to concentrate
for longer. And I want to emphasize that so much of our mental focus,
whether or not it's for cognitive endeavors or physical endeavors, is
grounded in where we place our visual focus, okay? What we look at and
our ability to hold our concentration there is critically determining
how we think. So, in other words, if you can hold visual focus, you
can hold mental focus, cognitive focus, but holding visual focus is
challenging, it's tiring, because it requires movement of the lens.
And that movement of the lens requires activation of muscles. And the
activation of muscles, as you know from the physical performance
episodes, if you saw them and even if you don't, is dictated by
neurons. So, what is accommodation? Well, it's actually very simple
and very elegant. And again, this is another case where whenever I
look at this stuff, even though I've been looking at for years,
learning about it for years, it still boggles my mind that we have
these apparati built into our eyes. So, we have lenses in our eyes,
and we have these things called the irises. You know, you're all
familiar with the iris, because you'll see people's pupils get bigger
or smaller, and we intuitively think of eyes as having the pupils. If
you actually draw two circles on a sheet of paper, and you just, they
look like two circles. But if you put little dots in the middle of
them, they look like eyes. Your brain recognizes those as eyes,
because one of the first things you see when you come into this world
are eyes. And actually, if you put the little dots close together,
it'll look kind of wrong, like it's cross-eyed. And if you put them at
different locations within those two dots, of opposing locations,
it'll look google-eyed. And so, your brain is actually filling in all
the face and other information, even emotional information, just based
on this recognition of eyes. And so, there's clearly we know this,
there's real estate deep up in, you know, further up in the brain,
that's responsible for analyzing and recognizing faces and the eyes
and the position of these little things we call irises, and pupils, et
cetera, is really important for how we interpret the status of others.
And that's why it's such a powerful thing just to put two circles and,
you know, move the pupils around on paper. In fact, I want to get into
accommodation, but if you think about it, if one of my pupils was up
there and the other one was down there, one was really big, and one
was really small, that would actually be a sign of pretty severe
damage. If someone gets hit hard on the side of the head, you'll
notice that they shine a light in one eye. You know why they're doing
that? They're actually looking at the other eye. When you shine light
of the eye that pupil constricts to limit the amount of light that
comes in, so it doesn't damage the eye. This also happens when you
walk outside, and it's bright, it constricts, but we have what's
called the consensual pupil reflex. There's a connection deep in the
brainstem, deep back here in the brain near my neck, that connects the
pupil mechanism for the two eyes, and they're looking at the other
eye. And if you shine light in one eye, and that people constricts but
the other one doesn't, there's a good chance there's brainstem damage.
This is what they do on the side of a, you know, football field or a
boxing match, or if someone unfortunately hits their head. So, two
pupils and don't freak out if one pupil is a little bit smaller than
the other, that doesn't necessarily mean brain damage. But if you
suddenly have one pupil bigger than the other, you absolutely want to
go see a neurologist right away. So, the eyes and the pupils are
indicative of things that are happening deep in the brain. Now,
accommodation is our ability to accommodate to things that are up
close here or further away. And the way this works is that the iris,
and the musculature, and a structure called the ciliary body move the
lens. So, when you look far away, okay, when you see things far away,
your lens actually relaxes, it can flatten out. So I want you to think
about this. When you look far away, when it may be anywhere from like
20 feet away from you out to a horizon that's miles or kilometers away
from you, the lens can just relax. It can flatten out. And you'll
notice that it actually is relaxing to look at a horizon. It's
relaxing to look far away. Whereas if I look at something up close to
me like this pen, or my phone, or a computer screen, or this
microphone, it takes effort. You'll sense the effort. Now, some of
that effort is actually eye movements, because you have muscles that
can move your eyes within their sockets. But a lot of the work, quote
unquote, is neural work of the muscles having to move and contract,
such that the lens actually gets thicker, in order to bring the light
to the retina and not to a location in front of it or behind it, so
called accommodation. There's also changes in the size of the pupil,
as things are closer and further away from you. In fact, there's a
simple way to think about this. Healthy pupils are going to dilate
when you look at something far away from you. Now, when you see
something that excites you or stresses you out, your pupils also get
big. Your eyes get wide. But if you look at something far away, your
pupils are going to dilate. And when you look at things that are
closer to you, when you move them up close, the pupils are going to
shrink. That's all part of this accommodation mechanism. Now, you
might say, why are you telling me about accommodation? This is crazy.
Why are you telling me about this? Well, these days we're spending a
lot of time looking at things, mainly our phones up close, and
computers up close, and we are indoors. If you are a young person, and
even if you are 25 or older, and you are spending a lot of time
looking at things up close, and you are not allowing your vision to
relax. In other words, you are not giving your lens the opportunity to
flatten out, and for these muscles to relieve themselves of this work,
you may or may not have migraine headaches. You may or may not have
headaches. You might, and that could be the cause of those. But you
are also training your eyes to be good at looking at things up close
and not far away, and as a consequence, you are reshaping the neural
circuitry in your brain, and it is not good. It is not healthy to only
look at things up close. Now, there are a lot of recommendations out
there right now, especially with all the lockdowns of the last, you
know, 12 to 18 months that people should look up from Zoom every once
in a while.
Or maybe now, I'm hearing that people should take calls instead of
doing Zoom, where you should look up from your computer screen. It's
actually not going to solve the problem, just to look up from your
computer screen. You need to go to a window. You need to look out at a
distance. Ideally, you would even open the window, because those
windows actually filter out a lot of the blue light that you want
during the daytime. A lot of the sunlight, it's actually 50 times less
gets through. You want to get out onto a balcony. You want to relax
your eyes and look out at the horizon. You want to go into what's
called panoramic vision, and let your vision expand. You want this
lens mechanism to be very elastic. You don't want it to get stuck in
that configuration of looking at things up close. Accommodation is a
wonderful feature of your visual system, but you don't want to push
that too hard, too often, or for too long. You want to view the
horizon. You want to get outside, not just to lighten the load on your
mind, or to think about other things, but to maintain the health of
your visual system. In other words, you want to exercise these muscles
and that involves both the lens moving and getting kind of thicker and
relaxing that lens. And the relaxation of the lens is actually one of
the best things you can do for the musculature of the inner eye. So
what's the protocol, how often should you do this? You might be
surprised, but for every 30 minutes of focused work, you probably want
to look up every once in a while and just try and relax your face and
eye muscles, including your jaw muscles, because all these things are
closely linked in the brainstem and allow your eyes to go into a so-
called panoramic vision, where you're just not really focusing on
anything and then refocus on your work. At least every 90 minutes of
looking at things up close, or even if you're looking at a screen, you
know, television screen, or you're watching a movie, or you're
indoors, for every 90 minutes of that, you ideally would have at least
20, probably more like 30 minutes of being outside, ideally. But if
you can't be outside, of non up-close vision. And you might say,
that's impossible, how am I supposed to do that? You know, I'm in an
office or I'm in a building. Get to a window, get outside if you can
do it safely, get onto a balcony, and just let your eyes relax. Many
people are experiencing severe vision problems, because they're not
getting enough sunlight during the day. They have sleep problems,
because they're not viewing sunlight early in the day. And as I've
mentioned in previous episodes, they're getting a lot of artificial
stimulation, artificial light stimulation, of the eye in the middle of
the night, all of this is through the visual system. So migraines,
fatigue, challenges with your eyesight getting worse as you age, or
even in young people, there's a, you know, at least according to the
articles, they describe it as this epidemic of myopia can largely be
dealt with by getting outside, going into panoramic vision,
experiencing some distanced vision, look at things off in the horizon.
If you're walking or hiking or biking, not looking at your phone the
whole time that you're doing that. If you're at the bus stop or you're
commuting, certainly not looking at your phone the entire time you're
doing that. So this is vital. And I want to emphasize another
protocol, though I don't want to get into it in too much depth, 'cause
I want to make sure that I also talk about a number of other important
aspects of the visual system that are more related to sight, but
getting into optic flow is very important for de-stressing your
system.
When you move through space, whether or not it's through walking,
biking, even swimming, if it's self-generated optic flow, so probably
not driving or motorcycling, but yes, bicycling or I don't know,
unicycling. I don't know why I thought about unicycling. There used to
be a graduate student at Stanford who was a really impressive
unicycler, those are pretty rare. As long as it's self-generated optic
flow, meaning you're generating motion of your body and the visual
images around you are passing by on your eyes, that is very good for
the visual system. And it's very good for the mood systems and the
neuromodulator systems of the brain and body that regulate mood. This
is well-established. So I'm not telling people to get away from their
phone and their computers. I spend a lot of time staring at a page,
drawing, writing, texting, et cetera, just like you do, but we're
really talking about some very simple protocols that aren't just
designed to improve your sleep, but are really designed to bolster and
enhance your vision. And of course, because it's this podcast, we will
also talk about things that you can take to improve your vision. But
if your visual behavior isn't right, and I do believe we should always
start with behaviors, and then think about nutrition, supplementation,
et cetera, if your behaviors around vision aren't right, you cannot
expect to have good, healthy eyesight for a long time, meaning
throughout your lifespan. And if your vision is already poor, many of
these things that I'm talking about today, perhaps all of them, will
improve your vision to some degree. And if your vision is starting to
go, then doing these behaviors is likely to really enhance the quality
of the vision that you will build and maintain over time. And all of
these are essentially zero cost, okay? If you live in a very dark
environment, like a cave or outer space, it's going to be hard to do
some of this stuff. But if you're on planet earth, even if there's
cloud cover, chances are you can do some, or most, or even all of
these some, most, or all days.
What I'm about to describe next is going to seem so silly on the face
of it, but has deep mechanism to support it. Put simply, when you get
tired, your eyelids close, and when you're alert, your eyelids are
open. That is because you have neurons in your brain, that depending
on your level of alertness, will make it easy or hard to keep your
eyes open. Now, that's a complete duh, except that we don't often
think about the relationship between alertness and where we are
looking and our eyelids. Now, I learned this from a colleague of mine
in psychiatry, who happens to work on hypnosis. I'm not going to
hypnotize you right now. That's actually for a future episode. But
what happens when we get tired? Our eyelids close, and our chin moves
down. We tend to nod out this way. If you have ever been in a
classroom, certainly not one of mine, but if you've been in a
classroom and the lecturer is kind of drawing on, or it's the
afternoon, what you'll notice is that a number of students, their
heads are jolt, kind of their eyelids are closing, and their chin is
dropping, and they, you'll see a bunch of heads bouncing back up,
right? I was definitely one of those people in class. If it was post-
lunch in the afternoon, it's warm, the hum of the air conditioner, or
whatever it is, and I'm just out, okay? When we're wide awake, the
opposite happens. Our eyelids are open all the way, and our chin
happens to be up. And no, this is not me telling you to have good
posture. However, what I learned from my colleague at Stanford is that
these circuits actually act in loops. When we look up, maybe it's
because these melanopsin cells are in the bottom of our retina, they
are, and maybe it's because they're there in order to view sunlight,
which is overhead, which it is, but that system of alertness is linked
to the position of our eyes. So when we look up and our eyelids are
up, it actually has a purpose. It actually creates a wakefulness
signal for the brain. And so, while this might seem like the silliest
and simple tool that I might ever describe on this podcast, if you are
feeling tired, it actually can be beneficial to the wakefulness
systems of the brain, including the locus coeruleus and these areas
that release norepinephrine to actually look up, to actually look up
toward the ceiling. You don't want your chin all the way back, but to
look up and to raise your eyes toward the ceiling and to look up and
try and hold that for 10 to 15 seconds. So this isn't looking up and
closing your eyes, like on a nice sunny day, that's relaxing. This is
looking up and actually looking up at the ceiling. It actually
triggers some of the areas of the brain that are involved in
wakefulness. So if you're somebody who's falling asleep at your work,
this can be very beneficial. Likewise, many people are looking at
their phone all day, and their chin is down, and then they're sitting
at a computer that's positioned below them, and they're having trouble
staying awake or focusing. It can be very, I tell Costello this all
the time, 'cause he's always falling asleep while he's trying to do
his work, positioning your computer screen up at eye level, or
sometimes having it actually above eye level, can actually create
wakefulness and alertness for the work that you're going to do. This
is simply because of this connection between the brainstem circuits
and the other neural circuits that control wakefulness and eyelids
opening and looking up. Okay, so it, again, it's remarkably simple,
almost laughably simple, but it's grounded in some of the most
hardwired, meaning present from birth, aspects of our neural
circuitry. And norepinephrine released from locus coeruleus isn't just
a mouthful, it's a really interesting and powerful mechanism for how
the rest of the brain wakes up. Locus coeruleus hoses the rest of your
brain with norepinephrine, in order to wake up those circuits for work
and attention. And so, eyes up is actually a way, a route into
increased alertness. Eyes down is a route into sleepiness, into
reduced alertness. And I have only one friend that texts up here, like
on the street holds his phone up here. It looks ridiculous. And yet,
you know, if we were trying to create more sense of alertness, if
that's your goal, positioning computer screens up high, chin up,
looking up if you need to kind of create an alertness signal, not
always being chin down and texting, or working into typewriters, or
reading below us. is actually going to send a recurring wakefulness
signal. When things are up, we tend to be alert. When everything's
focused down, including our eyes, it tends to have a more suppressive
or sedative type signaling to the deeper centers of the brain. Now,
before we move on to the science, and tools, and protocols related to
pattern vision, I want to mention another study that was done by the
University of Pennsylvania.
They have a terrific group there that works on sleep. They made an
important discovery that I think everybody should know about, which is
that children that sleep in rooms that have a nightlight or dim lights
are much more likely to develop myopia, nearsightedness. Conversely,
children that sleep in very dark rooms, so either very dim nightlights
or complete black, they have a much lower, statistically speaking, a
significantly lower probability of developing myopia, nearsightedness.
Now, why is that? It's because the wavelengths of light that matter
for these melanopsin cells, oftentimes can get through the eyelids.
And that's particularly true for children and people that have thin
eyelids. Some people, like me, have very thin eyelids. I've been told
this before. Not many people touch my eyelids, but among those that
have, I have very thin eyelids. I notice I have very thin eyelids
compared to say, Costello. Now, Costello's eyes droop. He can't even
close his eyes all the way they're so droopy. But many people have
thin eyelids, and those people are going to be even more prone to
light coming in through the eyelid. So for parents, for kids, and for
adults, you really want to try to get to a place where you can sleep
in a completely black or dark environment. One little exposure to
light, no big deal. But this ties back to the other protocol that I've
described before in the mood and sleep episodes, which is that viewing
light, even a very low intensity between the hours of 10:00 PM and
4:00 AM is extremely detrimental to the dopamine and other mood
producing systems of the brain. It can negatively impact learning, and
immunity, and even blood sugar, and make people type two diabetes
prone by way of communication from these melanopsin cells to a
structure in the brain called the habenula. Why am I throwing out all
this verbiage? Well, because people have asked for more mechanisms.
So, if you really want to know, when you look at blue light or if blue
light is getting in through your eyelids in the middle of the night,
it is likely distorting this lens accommodation mechanism in the eye
and leading to myopia in some cases. So, that's one reason to avoid
blue light exposure and bright light exposure, even nightlight
exposure, in middle of the night. Viewing any light of bright
intensity between the hours of 10:00 PM and 4:00 AM on a consistent
basis is going to suppress dopamine, because of the way that that
light activates these melanopsin cells, and the habenula, and the
dopamine system. So it's all very simple, get as much bright light as
you can safely, right? You never want to look at any light so bright
that it's painful look at, during the daytime. Try and go without
sunglasses, unless you need them. Now, I wear sunglasses for sake of
sport and sake when it's really bright out, but I try to get two hours
a day of working outside or being outside, even if there's cloud
cover, that's going to offset myopia. It's going to help you get
better sleep. It's going to support mood and metabolism, et cetera.
And at night, if you're sleeping with a lot of lights in the room, and
especially, if there are kids that need a nightlight, you should try
and wean them off that nightlight, because it's going to be beneficial
for their vision to wean them off that nightlight and put them into a
darker environment. Obviously, you want to get them emotionally
comfortable with that first. Now, let's talk about pattern vision,
actual seeing things, like faces and colors, et cetera.
I'm presuming that some of you out there are colorblind. We can all
help the red-green colorblind folks out there by not using red in
slides and diagrams, and on menus, and things of that sort. Try and
use magenta instead. They can see the contrast between magenta and
green better than if there's red and green. So, be kind to the
colorblind folks out there. It's actually a fair percentage. And there
are a lot of different kinds of colorblind. I should just mention some
people are true monochromats. They see the world in black and white.
That's exceedingly rare. Most colorblind people, colorblind in quotes,
are red-green colorblind, meaning they lack red cone photo pigment,
meaning they can't see long wavelengths of light. So they see the
world much as a canine or a cat does, where they don't get the green-
red contrast. That's why we call it red-green colorblind. They have
the green cones, but they can't do the contrast comparison that I
described at the beginning of the episode. So use magenta, and they
will be able to see things. You wonder why stop signs and stop lights
and things aren't in magenta. Well, because the world is unkind to the
red-green color blind individuals, and they have to learn the position
of those lights in the street lights. And they have to learn the
shapes of signs, which they can do readily, and it usually says stop
on it as well. But if you care about colorblind folks, which I do,
then we could all do them a service by, I think by law actually in the
U.S., menus are required to be colorblind accessible. How can you
improve your vision? How can you get better at seeing things?
Well, one way is to make sure that you spend at least 10 minutes a day
total, at least, viewing things off in the distance. So that would be
well over half a mile or more, try and see a horizon, try and get your
vision out to a location that's beyond the four walls of your house or
apartment, or the doors of your car, and the windshield of your car. I
know that can be hard to do, but it's very valuable. If you live in a
city like New York and it's skyscrapers everywhere, you've probably
experienced the incredible sense of relaxation, and it's aesthetically
beautiful, when you are walking down one of these long avenues, and
you turn, and I think they have a name for this in New York, where the
sunset is suddenly visible along a long avenue between some
skyscrapers. And it's just very relaxing to be able, suddenly, to see
at a distance, and that's actually because this eye mechanism of
relaxing the lens and relaxing some of the musculature around the eyes
sends signals deep into the brainstem that release some of the centers
that are involved in alertness, AKA stress. And it's very pleasant for
a reason. It's not a, it's not a placebo effect if you will. There are
a bunch of neurochemicals and things that are associated with that. So
try and see at a distance, because it's good for your eyesight. It'll
keep this lens nice and elastic, and the muscles nice and strong that
move the lens, and it has this relaxing component to it. Now, our
visual system is exquisitely tuned to motion, not just our self-
generated motion, but the motion of things around us.
And one of the things that it does is something called smooth pursuit.
Smooth pursuit is our ability to track individual objects moving, as
the name suggests, smoothly through space in various trajectories. You
can actually train or improve your vision by looking at smooth pursuit
stimuli, and that sounds really boring. What you can do is, and I'll
provide a link to some that I think are pretty good that are used in
various clinics, ophthalmology and optometry clinics. You can actually
take a few minutes each day, or maybe if you don't do it each day, you
could every third day or so, and actually just visually track a ball.
Sometimes it's moving in and kind of an infinity symbol. Sometimes
it's more of a sawtooth. Sometimes it's changing speed. Sometimes the
cue that you're following, the little target, is dilating and
contracting. This is going to keep the muscles, I want to be clear,
this is going to keep the extraocular muscles conditioned and strong
and allow you to have a healthy smooth pursuit system. Remember, the
brain follows the eye. It follows the movements of the eye. It has to
deal with that. And the neural circuits within the brain have to cope
with changes in smooth pursuit. So if you're doing a lot of reading up
close, you're not viewing horizons, you're not getting a lot of smooth
pursuit type stimulation from your life, or you're just getting it
within the confines of a little box on your phone, like your smooth
pursuit is over, you know, millimeters or what we always talk in terms
of visual angle, but the amount of degrees of visual angle. But if
you're just looking at smooth pursuit in this little tiny box on your
phone, or on your computer screen, and you're not looking at objects
in your environment like swooping birds and things like that, which
I'm guessing many of you are not spending your time doing, well, these
mechanisms for smooth pursuit will get worse over time. Your vision
will get worse. And so, while I prefer that people get out into the
real world and experience smooth pursuit tracking of visual objects, I
don't know, maybe it's a good reason to go to a hockey game or, you
know, and try and keep your eye on the puck, which I can never seem to
do. It moves so fast. Or I guess this is a good reason to watch live
sports if that's your thing, or to watch a tennis match, like a cat,
like a kitten, watching the ball go back and forth, whatever, watching
kids play, it doesn't really matter. The idea is that you want to use
the visual system regularly for what it was designed for, and smooth
pursuit is a great way to keep the visual and motion tracking systems
of the brain and the eye and the extraocular muscles working in a
really nice coordinate fashion. I would say five to 10 minutes, three
times a week will be great. If you care about your vision, you can
train your vision in this way.
The other one is to train accommodation. There are a lot of videos out
there, I want to be clear, on the internet, some of which are from
clinicians, some of which are not. Some of which are from scientists,
some of which are from other sources, talking about things you can do
to make your vision better, to improve your vision. Most of those are
geared toward improving the extraocular eye muscles, but I did consult
with our chair of ophthalmology at Stanford School of Medicine, Jeff
Goldberg, who's an MD and a PhD, a phenomenal scientist, and a
phenomenal clinician, and incidentally, a phenomenal chairman as well,
about what sorts of things, tools, are actually beneficial for pattern
vision and sight, because there's just so much out there on the
internet. Not all of which is accurate or good, frankly. And he agreed
that a smooth pursuit stimulus, that kind of training, as well as, or
exercise, as well as near far. So spending a few minutes, you might
even just do this for two minutes of looking at something up close,
that's going to activate these accommodation mechanisms, and then
moving it at arms length, and focusing on it for five, 10 seconds,
maybe more, maybe 15 or 20 seconds, then slowly moving it into a
location, and then out. This is actually a lot like the visual
training that's done post-concussion to try and repair, actually
repair some of the balance, and motor, and visual, and cognitive
aspects of the brain. And we are going to have a guest on at a future
time that, to deal with concussion and some post-concussion training.
A lot of post concussion recovery and training centers around the
visual system. Not just because people are trying to recover their
vision and their sense of balance, but because, as I mentioned
earlier, the brain's ability to make sense of its environment, and the
brain's ability to parse time, not just on the day-night schedule, but
also shorter time intervals, follows the visual system. Something
we'll turn to a little bit more at the end. So what does this mean?
The tool is, spend two to three minutes doing smooth pursuit. There's
some programs on YouTube, or you can just look up smooth pursuit
stimulus, and I'll provide a link to a couple I like as well. You
could do this with a pen if you wanted. You could do this. Someone
else could hold a wand, and you could do that, if you've got someone
that can do that for you. Practice accommodation for a few minutes,
maybe every other day, just bringing something in close. You'll feel
the strain of your eyes doing that. I can feel it right now, move it
out. You'll feel a relaxation point. Move it past that relaxation
point, where you will have to do what's called the vergence eye
movement to maintain focus on that location as it moves out, bring it
back in. At the point where you actually have to go cross-eyed, this
will differ for different people, depending on how far apart your eyes
are, so called interpupillary distance. So for me, I have been teased
before, I have a very short interpupillary distance. I'm not a
cyclops, but I'm heading there. Some people are more walleyed, like a
flounder. Well, depending on your interpupillary distance, the point
at which things get blurry and cross-eyed will vary. But for me, you
know, as I get about, oh gosh, I guess it's about six inches from my
nose. It's really hard, I can't accommodate any longer. I move it out
another inch, and everything's in nice focus. Try and see whether or
not you can get things closer. Now, you don't want to get cross-eyed.
Remember what your parents told you, or my parents told me, that if
you cross your eyes, when you're young, that they can stay that way.
Actually, they won't necessarily stay that way, but your brain can
start losing information and the ability to see binocular depth,
something we'll talk about in a moment. But for now, the protocol
would be, you know, two to three, maybe five minutes, just practice
that, practice accommodation, and then be sure to give your eyes some
rest, get outside, look at a horizon, or do nothing, just kind of let
your eyes go soft. I guess what the yogis would call soft gaze. Just
kind of relax your eyelids, not this, not eyes closed. Just relaxed,
panoramic vision, try and see the walls around you without moving your
head. Exercise your eye muscles, exercise the accommodation mechanisms
of your eyes, practice a little bit of smooth pursuit. You don't have
to be neurotic about this, but if you do this often enough, meaning
every other day, every third day or so, you can be the strange person
on the plane or in the classroom doing this. You know, that people
might chuckle or look at you funny, or tease you, but that's okay,
because you'll be able to see when they are losing their vision, so
you'll get the last laugh. Please don't laugh at them, but maybe you
can help them. At that point, you can hold the pen for them. It's
worth doing. It's really worth preserving your vision. And again, if
you're a young person, this is great, because then you can actually
build an extra strong visual system, using all the tools that we're
describing. I do want to talk about a new set of findings that are
related to red light and offsetting age-related macular degeneration.
There are a lot of ways in which our visual system gets worse over
time, but one is so called age-related macular degeneration. Glen
Jeffrey at the University College London, somebody I've known for
decades as a, because he's a scientist, has done beautiful work on
development and function of the visual system, has published a number
of papers recently, one that got a particularly high amount of
attention in the press was one that showed that flashing red light
into the eyes early in the day, not late in the day, early in the day,
can help offset some age-related macular degeneration, presumably by
enhancing the mitochondrial function in the photoreceptors. There does
seem to be some evidence for that. Although, it's still early days, I
want to emphasize you don't want to shine really bright lights into
your eyes. You never want to look at any light that's so bright that
it's painful, and you never want to force your eyelids to stay open.
If you need to close your eyes in order to be comfortable, well, then
chances are that light is too bright. But doing just a couple minutes
a day, like two minutes a day of flashing this red light into one eye,
and then the other. As long as it was early in the day before noon
time, and as long as it was in individuals that were 40 years or
older, did seem to have a significant effect in offsetting some of the
age-related macular degeneration that would otherwise occur. Again,
these are early findings. If you want to do this, please be careful.
Please talk to your optometrist and/or ophthalmologist. Your eyesight
is precious. You don't want to damage it, but it is interesting. And
it does seem like red light can improve the function of the
mitochondria. These photoreceptors have a lot of mitochondria, the
energy-producing organelles within the cells, because they are some of
the most metabolically active cells in your entire body. Your
photoreceptors are active all the time as you're looking around, and
even when your eyes are closed, they're active. In fact, through a
weird twist of the biology, and please look this up if you're really
interested in this, your photoreceptors are actually most active in
the dark. This is so weird. It's a twist of biology, the way the
system's arranged, that when light comes on, they shut off their
activity. So actually whether or not you see something in front of
you, like this pen or my face, is because the way your photoreceptors
are turning off not turning on. It's a really cool twist, and I don't
want to go too far down that rabbit hole, but check it out if you're
interested in how photoreceptors work. It's an absolutely incredible
literature. Just Google, excuse me, look up on the web. We are not
partial just to Google. I happen to use Google, but use your web
browser to look up photoreceptors hyperpolarization site. And you can
learn a lot about that, if you're a real nerd for this stuff, like I
am. Okay, so red light to the eye, can perhaps, it seems, help
maintain vision, doing smooth pursuit exercises, and accommodation
near-far exercises.
Some people suffer from poor eyesight, simply because their eyes get
dry. There are incredible, believe it or not, lubricating mechanisms
for the eye, not just tears, but a thin sheet of oil. I mean, it's
just amazing. Unless you have some sort of corneal abrasion, the
cornea is the clear stuff on the outside of your eye, corneal
abrasion, when you blink, it's smooth, you don't feel it. It's just
really, really smooth. And yet, if you've ever had a corneal scratch,
I've had this, it's really rough, it is so painful. You have a ton of
pain receptors in the cornea. The lubrication of the cornea is
supported by blinking. And while it seems a little silly, some people
actually benefit from doing some, you know, five or 10 or 15 seconds
of blinking, and then doing their focused work. Some people, their
eyes are drying out, because as we focus, if we're trying to do
something, our eyelids stay open, the eyes can dry out, but it also
can make it such, that when we blink the next time, there's a kind of
a need to focus, because there's some distortions in these oils and
liquids across the corneal surface. If you're somebody who suffers
from dry eye, I do hope they'll find a treatment or a cure for dry eye
soon. There isn't one at present. Someone stands to make a lot of
money out there if you can find a cure for dry eye. Let the companies
know or start a company, right now it's still a mystery as to how to
do that. But blinking for five 15 seconds, probably slowly, not as
quickly as I'm doing here on video, but just, you know, maybe a blink
every a second or two for 15 seconds can lubricate the eyes. And
that's not directly related to anything neural, it's just going to
allow the optics of your eye to be clear. Just like when the screen of
your phone gets dirty, like when Costello's texting on my phone, and I
pick it up, and it's like covered with smudge, to clean it off in
order to see things clearly, the same thing is happening for these
optical devices on the front of your brain. Remember, these are brain.
Okay, so a lot of protocols today, almost all of them behavioral
protocols. I do want to talk a little bit more about vision and how it
works internally. And then I also want to talk about some of the foods
and supplements that have been shown to support vision and offset
visual loss, and maybe even reverse some visual loss. Let's talk about
binocular vision and lazy eye.
I'm very familiar with lazy eye, because when I was a kid, I went
swimming one day, one day, and I didn't have my goggles. And so,
something must have been happening, as I recall, with the eye moving
down through the water, I've always had this problem that I can only
do the freestyle stroke off to one side. The people I swim with are
always laughing. Somehow, I kind of move toward drowning when I try
and breathe on the right side. I think there's some asymmetry in the
way I'm organized. Anyway, I was off to my left, and my eye kept going
in and out of the water, and there was chlorine in the water, and it
was making my own uncomfortable, so I just closed my eye. I just
decided, you know, I knew more or less how to swim straight-ish.
Might've bounced off the lane lines a few times, but I just use the
other eye to kind of steer for that mark on the wall. Got out of the
pool, took a shower, dried off, and then completely lost by binocular
vision for three days, completely. The young brain, up until about age
seven, but maybe even extending out until about age 12 is extremely
vulnerable to differences in ocular input between the two eyes. My
scientific great-grandparents won the Nobel Prize for discovering so
called critical periods, periods of time in which the brain is more
plastic, more able to change. Those two guys, David Hubel and Torsten
Wiesel, thank you, David and Torsten, forever changed the face of
visual neuroscience and forever changed the way we think about
treatment of the young brain. It used to be thought that you wouldn't
want to do a surgery on a young kid, because of risk of anesthesia in
young individuals. But we now know that you need to repair these
imbalances, that even a few hours, okay, I don't want to scare
anybody, I'll talk about reversal. But a few hours of occluding one
eye early in life can lead to permanent, unless something's done,
permanent changes in the way that the brain perceives the outside
world, such that when that eye is opened up again, the brain actually
can't make sense of anything that's coming through it. It shuts down
that visual pathway somehow. So what happened to me was, I actually
was, my eye was fine. I got out of the pool, I opened my eye, but I
couldn't see through that eye. Everything was blurry, double vision,
unless I covered this eye, and then I could see perfectly fine.
Fortunately, I went to an ophthalmologist who understood the
literature. Thank you, Dr. Mark Lurie, who understood the literature
and made it clear that what I needed to do was to occlude the other
eye, the eye that was working very well. Clearly, he understood the
work of you Huber and Wiesel. Now, again, you don't want to start
playing games with this kind of stuff when you're a kid. If you wear,
let's say you have a Halloween costume and you wear an eye patch,
you're a pirate or something for Halloween, and you cover it up on one
side, probably for the night of Halloween, it's okay. I do not
recommend doing that recreationally if you don't need that if you're a
young child or for your child to do that. Because, indeed, you create
imbalances in the brain machinery that compares information coming in
through the two eyes, and it can shut down the neural information for
the occluded, the closed eye. Now, I was able to reverse this issue,
but my binocular vision has never been terrific. I'm much better at
the dart board and still not very good if I close one eye. I'm much
better at the pool table, if I close one eye, and I still am terrible.
I was the kid in, you know, in the outfield. You know, the ball is
coming towards me, the ball's coming towards me, I'm going to catch
the ball, and like it hit me square in the lip. My binocular vision
isn't great as a consequence of this early event. And I have a hard
time with those binocular stereograms, those images that are kind of,
you're supposed to look at them, and then the binocular depth image
like pops out. All the other kids were going, oh, there's the,
whatever, the Statue of Liberty. There's the [inaudible], and I see
dots. Okay, so I have binocular vision, but I use other cues. I use
the near-far cues that I talked about before. Motion parallax, the
fact that things are closer to me are moving faster than things
further away, in order to judge depth. And years later, when I got
involved in, and I don't suggest this for most people, I got involved
in boxing and martial arts when I was younger. You sometimes will see
fighters, this is a slip to avoid getting punched. It's also
generating motion parallax. Many animals judge depth by moving their
head, not by using other mechanisms of accommodation, okay? So a lot
of birds and monkeys and animals will judge depth by moving their head
like this, or they'll move from side to side. Animals that will
undulate sometimes are actually doing a depth measurement, because as
you move from side to side, the brain is able to do the math of depth.
So what does this all mean in terms of protocols? If you're a young
person, do your best to get really good binocular vision, not just at
level of your phone or your tablet, but also at distance, you will
build strong binocular visual machinery in the brain and at the level
of the eyes and the eye musculature. Now, if you're somebody who did
have an occlusion, what's needed is to cover up the other eye to
create an imbalance, so that the weak eye, the so-called lazy eye,
this is sometimes referred to as amblyopia, that eye has to work
harder. So for me, they patched this other eye and made this eye,
eventually, I got vision through that eye back. then they opened them
both up. Now, you might ask, what happens if you cover both eyes early
in life? And this is where it gets interesting. You might think, well,
if covering one eye leads to poor vision for that eye after that eye
is open, covering both eyes will probably make you blind, right?
Actually, that's not what happens. What Hubel and Wiesel discovered
and what's been affirmed many, many more times over in subsequent
studies is that it's competitive, that the two eyes are competing for
real estate up in the brain. So if you actually cover both eyes, you
actually extend the period of critical plasticity. This is a really
interesting aspect that other people are starting to leverage now, in
terms of how to reopen plasticity later in life. But please don't, you
know, go around with your eyes covered for too long. There are some
like retreats and stuff where people go into caves with absolutely no
vision. It creates hallucinations. We'll talk about why that is in
just a moment, but here's my suggestion. Try and get balanced visual
input through the two eyes. Almost everybody has a dominant eye. It
usually doesn't relate to your dominant hand, although it can.
And so for me, if I cover up my right eye, I see much less well, much
more poorly. It's a little bit fuzzy, and I have to work harder in
order to see the camera for instance. Then, if I cover up my left eye,
it's actually really easy for me to relax. I have a dominant eye. Now,
you can balance that out by covering up the dominant eye a little bit
each day, but I would warn any young people, meaning, you know, 12 or
younger, against creating these imbalances if there isn't a clinical
need to do that. And if you do have strong imbalances between the two
eyes, which can be caused by cataract and lens issues, can be caused
by neuromuscular issues, et cetera, to try and get those dealt with as
early as possible by contacting a really good ophthalmologist and
ideally a neuro-ophthalmologist. It is very normal, I should say, it's
very common for young children, babies to have an eye that, with
strabismus, that either deviates out or that deviates in. It is
important to correct that. If you would like to have balanced division
between the two eyes and for the brain to respond equally to the two
eyes and to have, I would say high fidelity, quality vision. Although
some people who have an eye that drifts can function normally in life,
you have an opportunity early in life to rescue that. I won't do,
well, maybe I will do this, but I can actually relax this eye. It's so
weak, in some cases, that it actually can start to deviate. Here, I'll
just do this here. It's not crossing my eyes. So I actually can move
my, I can misalign my eyes, because I have to fight very hard to have
the musculature for this eye, keep that eye aligned with the other
eye. And that's because I've been doing eye exercises, since I was in
my twenties, 'cause I noticed when I would study a lot, this eye would
start to drift in, I'd start to see double, and I would then, next
thing you know, I was just covering the eye up, and it was getting
weaker and weaker, just like the atrophy of a muscle. So I went to the
doctor, what did they do? They did the exact wrong thing. The
optometrist I went to gave me a prism, which adjusted it so that I
could see things normally, which just made the eye weaker and weaker.
It's like putting a weak arm into a sling. So I had to spend at least
three years of 10 minutes a day, is what I recommend, doing near-far,
covering up my good eye, doing near-far with my bad eye. And now, it's
been about 10, 12 years that I have pretty decent binocular vision.
Now, many of you aren't dealing with this, or have these early
childhood issues. Some of you might be experiencing challenges with
fatigued eyes or with differences in focus with the two eyes. These
eye exercises of near-far, smooth pursuit, and checking for dominant
and non-dominant eye can be very beneficial. I'm again, I'm not a
clinician, so I don't want to, you know, give you protocols or enforce
protocols on anybody. You need to figure out what's right and safe for
you, given your vision history. I do recommend talking to a really
good ophthalmologist if you have severe vision problems of any kind,
or if you want to offset vision problems of any kind. An optometrist
as well, but ideally would be a neuro-ophthalmologist. Okay, I did
mention hallucinations, and they're fun to talk about and think about.
And for years, people have asked, why do people get visual
hallucinations. Costello's in sleep right now, you can probably hear
him snoring, he's snoring so loud. He's probably having hallucinations
about rabbits, pizza, and those are mainly his favorite, and sleep.
He's dreaming about sleep in sleep. Hallucinations are a property of
the visual system, and it was always thought that hallucinations
arise, because of over-activation or activation of certain aspects of
the visual system. I just briefly want to mention a paper that was
published by my good friend and phenomenal scientist and physicist for
that matter, Cris Niell who's up at the University of Oregon in
Eugene. They studied LSD light compounds and discovered that
hallucinations actually occur, because portions of your brain become
underactive. The visual portions of your brain are under-stimulated.
This is probably why, when people go into these cave retreats,
something I've never done, I don't think I ever will do, where it's
completely black, pretty soon, they start hallucinating. They start
seeing things, even though there's nothing there. The visual system is
desperate to make guesses about what's out in the world. It's like the
eager beaver of your brain. It's like, what's out there, what's out
there, what's out there? Even in low to no vision people, blind
people, they are, their brain is going to be making guesses about
what's out there in the auditory world. What sounds are there? What
touch sensations are there? For sighted folks, it's going to be,
what's out there in terms of light? Light is the dominant way. Vision
is the dominant way that we evaluate the world around us. So it turns
out that hallucinations are an under-activation of the visual system,
and then a compensatory, a compensation, by which the visual system
creates activity and hallucinations. So if you're in the dark long
enough, you start to hallucinate and see things. So, that's a little
note about hallucinations.
One of the things that you can do to improve your vision, and it's
also kind of fun is to put a Snellen chart in your home. A Snellen
chart is that list of letters. Or if you go to the dreaded Department
of Motor Vehicles, actually I'm up for renewal soon, so I love the
Department of Motor Vehicles. The Department of Motor Vehicles,
they'll have you cover up an eye, read the letters on the chart, the
letters of course gets smaller and smaller, they're trying to figure
out roughly what your vision is. Cover up the other eye, you'll do
that. Some people including nerdy, vision scientists like me have had
Snellen charts in their office or in their home for many years now,
and you can just practice, and you can see how you're doing sitting at
a particular distance. Your, this is something that's not often
mentioned, but your performance on the Snellen chart will vary
depending on time of day, because your level of fatigue and your
ability to control that accommodation and other mechanisms of the eye
muscles will vary, so you can take it as an average. It's also a good
thing, if you're going to get your vision tested for corrective
lenses, or maybe you're going to do laser surgery, or something of
that sort, if you're thinking about any of that, to really get it
measured by a professional. The ones that you get in those
supermarkets, or in many eyeglass stores, apologies to the eyeglass
stores, are often wrong by an order of magnitude. And then, when you
start putting corrective lenses on that are over-correcting or under-
correcting, but more often are over-correcting, well, then you're
essentially weakening the system. It's like putting a prosthetic on a
limb that you didn't necessarily need, or robot arm when you didn't
need the use of the robot arm. Although now there's so much excitement
about robots, I think people are going to be doing that anyway.
Nonetheless, get your vision tested by somebody who really understands
vision, like an ophthalmologist or a really good optometrist. If you
put a Snellen chart in your home, you know, you can do that as part of
your visual training. Now, this might seem excessively nerdy, but what
is more important than your eyesight, right? Eyesight is so vital.
It's right up there with movement and our ability to move, to
generate, to get up out of chairs, and to walk and to run, and to take
care of ourselves. Eyesight and movement are the main ways that we are
able to take care of ourselves and take care of others. When you start
having compromised eyesight or compromised movement, people need to
take care of us, and we become much more challenged in moving through
our daily life. So while it might seem nerdy to have a Snellen chart
in your home, or to do a smooth pursuit exercise a couple of times a
week, or to get outside for a few hours a day and do your reading or
your laptop work there, preserving your eyesight and preserving your
vision is one of the most life-enhancing or quality of life enhancing
things that you can do. And if you're a young person, and you can
build some of this into your framework of exercise or brain training,
if you want to call it that, that can be immensely beneficial and will
really set you up to have really good vision over a long period of
time. Now, of course, there are genetic factors, and there are injury-
related factors that can compromise eyesight and our ability to see.
And, of course, the things I'm talking about today aren't going to
solve all those issues, but they can have a tremendous, positive
impact if you're willing to do just a little bit of work, and none of
this is involving any cost, right?
It's just time cost. So I want, I do want to talk about a few other
things that can perhaps improve vision. I want to dispel a few myths
about stuff to take to improve vision. And then, I want to just close
by talking about how we perceive time using our vision, because that
will nicely set the stage for what we're going to talk about next
episode. So now, you understand a lot about the biology of vision. You
understand that light has to arrive at the retina and get converted
into electrical signals. That process requires things like vitamin A,
a fat soluble vitamin. It requires things like the carotinoids. That
metabolic cascade, the biochemical cascade, is essential for vision.
And this is why you've been told that carrots help you see better
'cause they're high in vitamin A. There are a few simple things you
can do to support your vision. First of all, it is true that eating
vegetables, the dark, leafy vegetables and things like carrots that
have vitamin A in abundance, and eating them in close to their raw
form, so naturally occurring foods that contain a lot of vitamin A in
their raw form can help support vision. Now, does that mean that if
you ingest super physiological amounts of that stuff, that it's going
to make your vision that much better? No, but you do need a threshold
level of vitamin A in order to see and in order to see well. Now,
there's a lot of excitement nowadays about supplementation to help
support the health of the visual system. And I'm somebody who's pretty
open to novel forms of supplementation. You've probably gathered that,
if you've been listening to this podcast for awhile. You have to
determine what's safe, and economical, and right for you, what your
risk tolerance is, et cetera. But I want to talk about a molecule
that's in a lot of supplements to support vision, and there are some
really good data on, and that's lutein. Now, the study I want to
describe is actually published in 2016. It's from the Journal of
Ophthalmology. It's a good journal. And the title of this paper is, it
might catch your attention, it's "Increased macular pigment optical
density," that just means that macula, is an area of the eye for
central vision, for high acuity vision. Pigment density there is good,
you want pigment there. "Increase macular pigment optical density "and
visual acuity," Visual acuity is your ability to see things in fine
detail. "Following consumption of a buttermilk drink "containing
lutein-enriched egg yolks." Remember, raw foods? Lutein-enriched egg
yolks. Sounds like a Rocky movie, where he would drink the raw egg
yolks. "A randomized double-blind placebo controlled trial." Now, I'm
not suggesting you go out and eat raw egg yolks. There's the risk of
salmonella. Although, I did hear this, someone correct me if I'm
wrong, but the salmonella is actually on the outside of the egg, not
actually in the egg itself, it's on the shell. For reasons that relate
to how that egg got into the world, that's where the salmonella lives,
but I could be wrong about that. But raw egg yolks are not something
that most people want to consume. What is this lutein stuff? Well,
lutein is in the pathway that relates to vitamin A and the formation
of the OPs in the photopigment that captures light in the back of your
eye, literally absorbs light pigment in your eye, and converts that
into electrical signals, and allows you to see. And there is some
evidence, I spoke to our chair of ophthalmology, there is some
evidence through quality peer-reviewed studies that supplementing with
lutein can help offset some of the detrimental effects of age-related
macular degeneration. But, I want to emphasize but, or emphasize
however, only for individuals with moderate to severe macular
degeneration. For people that have normal vision, or with a, just a
low-degree of macular degeneration, these studies did not see a
significant improvement of vision from supplementing with lutein. So,
I'm not going to to tell you to supplement with lutein or not. I don't
think any study is holy, but it does seem that if you have moderate to
severe macular degeneration, talk to your physician, of course, talk
to your ophthalmologist, I'll always say that, and I'll say it three
times, supplementing with lutein could perhaps support vision and
offset some vision loss in that case. Probably also talk to your
ophthalmologist or consider the red light therapy that I talked about
earlier. Whereas, if you have normal vision, or a low amount of
macular degeneration, it does not seem, at least from these studies,
that lutein had much of an effect. Now, I know, and I confess I'm sort
of of the mind that if I personally had age-related macular
degeneration, or a propensity for it in my family, which fortunately I
don't, but in that case, I would think that supplementing with lutein,
provided it's safe, could perhaps be of benefit. You might want to
consider a low dose of that. So again, I'm not pushing any of this on
anybody by any means, but you should know that, under certain
conditions of severe macular degeneration or moderate macular
degeneration, it does seem like lutein can be beneficial. It does not
have to be consumed through raw egg yolks, although that is the
highest density source. Cooking the egg yolk, cooking your eggs, if
you like your scrambled eggs dry, or you like your eggs not easy over
or whatever, not runny, then you aren't going to get the benefits of
the leucine. There are other sources of leucine, non-animal sources of
leucine as well. You can look those up on the internet. Now, there are
other compounds that have been shown to perhaps be important for
offsetting or helping different forms of vision loss. One is, I'm
going to spell this out, I-D-E-B-E-N-O-N-E, idebenone, idebenone,
idebenone, I can never pronounce these compounds, forgive me, unless
I've worked with them. There is evidence that it can be beneficial for
Leber's congenital eye disease. I would definitely go on to
examine.com, put in I-D-E-B-N-O-N-E. And for things like Leber's optic
neuropathies, which is a degenerative condition of the eye, whether or
not people should just be taking this stuff anyway is still an open
question. There aren't a lot of studies about it. A lot of people that
are interested in taking things to support their vision are taking
lutein as a preventative measure. I don't pass any judgment one way or
the other. Typically, those supplements also include the zeaxanthins
and astaxanthins. Okay, the pronunciation of this is terrible, I'm
sure, but that's not too far off, but basically Z-E-A-X-A-N-T-H-I-N.
You can see why it's hard to pronounce, Z-E-A-X-A-N-T-H-I-N. And the
other one is A-S-T-A-X-A-N-T-H-I-N. Both of these have been shown,
excuse me, both of these have been shown to offset some of the
disruption in vision that occurs with aging. What is astaxanthin? It's
a really interesting compound. It's the red-pink pigment found in
various seafoods. So shrimp, I'm not a big seafood fan, but like
certain fish, like the, you'll see at the fish market will have that
red-pink pigment. And it's also in the feathers of flamingos, please
don't eat the feathers of flamingos, and please also don't eat
flamingos. It's structurally similar to betacarotene, so it's very pro
vitamin A, but it has some chemical differences, which may make it
safer than vitamin A. Remember, vitamin A is a lipid-soluble vitamin,
so it can be stored in our body for long periods of time. What is the
deal with this astaxanthin? You know, what are its drawbacks? Well, we
can go to our ever favorite examine.com. What does it do? Well, it has
a number of different effects, a huge number in fact, but it does seem
to notably increase, it's now been shown in three studies, the
antioxidant enzyme profile. It has a number of different effects, but
the most notable for sake of this episode, is the one on ocular blood
flow. It does seem to increase the amount of ocular blood flow, so the
blood supply to the eyes, so that makes it an interesting compound. It
has a number of other effects. For whatever reason, it also has a
notable effect, several studies have shown this, on fertility in
males. So it seems to at least double the pregnancy rate when men take
astaxanthin and works as, in particular, it seems here in men that
were previously infertile. So, I don't know if that has something to
do with the blood flow to the eyes, probably not. It probably has
something to do with something unrelated to the eyes. Nonetheless,
that's an effect of this molecule. It's also been shown to have
positive effects on things like skin elasticity, skin moisture, skin
quality, et cetera, probably due to its effects on blood flow. So
lutein, astaxanthin, A-S-T-A-X-A-N-T-H-I-N, and for people who have
concerns about Leber's optic neuropathies, which is going to be a
small percentage of people out there, but that is a pretty severe
condition, there are supplements that are available out there. I do
encourage you, as always, to talk to your ophthalmologist and
physician about them. And I will say that there are a number of people
that take lutein and some of these other things as a precautionary
measure, in order to bolster their health in the same way that some
people take vitamins and minerals to bolster their health, and some
people are very health, excuse me, and some people are very averse to
taking vitamins and minerals, 'cause they feel like they can get all
that from healthy, whole foods. And of course, you can get these
things from whole foods. The question is whether or not you can get
them in concentrations that are sufficient. I do think that in the
years to come, we are going to see more about lutein. I think we are
going to see more about some of these other compounds like
astaxanthin, and hopefully by then I'll be able to pronounce it. But,
at present, these things are more or less in the kind of experimental
or self-experimental phase. There are some good double-blind placebo
controlled studies, like the egg yolk buttermilk study of all things
published in really good journals. Journal of Ophthalmology, Journal
of Investigative Ophthalmology and Vision Sciences, these are good
journals. These are journals are peer-reviewed by experts. The study
that I mentioned earlier about keeping rooms dark that was also
published in an excellent journal, I think it was JAMA. I'll go back
and look, it's not on my screen any longer, but very easy to find, and
there been some follow-up studies as well from the University of
Pennsylvania and other universities. So everything I've talked about
today relates to studies that were done and published in quality,
peer-reviewed journals. That doesn't necessarily mean you want to run
out and start taking this stuff that I've described, or even doing the
protocols I've described, I've given you an array, a palette, a buffet
if you will, of things that you could do to try and enhance or support
your vision.
Depending on how good your vision is, your family history of vision
and vision loss, your occupational hazards. You know, people that work
with metal filings that are flying out of machines are going to have a
higher degree of vision, you know, risk to their visual system than
well, people who just do office work. Although, if you're doing a lot
of office work, chances are you're not getting a lot of long-view
vision. Your accommodation mechanisms are going to start to suffer
over time. I think we can reliably predict that. So I've tried to give
you an array of behavioral tools, and we did touch upon some
supplementation tools. I'd be remiss if I didn't say that, because
blood flow is so critical for the neurons of the eye, remember, these
are the most metabolically active cells in your entire body, the cells
within your retina, because blood flow is required to get them the
energy and nutrients they need, having a healthy cardiovascular
system, right, doing endurance work, doing strength training work
regularly, is going to support your eyes, and your brain, and your
vision. It's indirect, but it's essential, right? It's necessary, but
it's not going to be sufficient. You're going to have to do other
things to support your eyesight, as well. But having a healthy
cardiovascular system, because it's going to deliver blood and oxygen
and nutrients to this incredible apparati on the front of your face,
these two pieces of brain, is going to support your overall brain
health and vision over time. So early in the podcast, I talked about
how the optimal window for learning is 90 minutes. That's the so
called ultradian cycle for learning. That's why we had all our
episodes to about 90 minutes. They're now starting to extend into the
hour and 50 minute and two hour mark.
That simply reflects my enthusiasm and excitement about these topics
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Link to eye exercise videos for smooth pursuit, amblyopia, etc.
(Numbering of videos does correspond to numbers in episode caption.)
https://www.youtube.com/c/VisualExercises/videos
Please note that The Huberman Lab Podcast is distinct from Dr.
Huberman's teaching and research roles at Stanford University School
of Medicine. The information provided in this show is not medical
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Title Card Photo Credit: Mike Blabac - https://www.blabacphoto.com