Essentials: Protocols to Improve Vision & Eyesight

**Andrew D. Huberman** (0:00)
Welcome to Huberman Lab Essentials, where we revisit past episodes for the most potent and actionable science-based tools for mental health, physical health and performance.
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. 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. When we hear the word vision, we most often think about eyesight or our ability to perceive shapes and objects and faces and colors. 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. 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. 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. 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. They aren't just aesthetically nice. 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. 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. 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.
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. 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. They're called retinal ganglion cells. 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 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. 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. 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. 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. 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 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 carryover 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. I'd like to take a quick break and acknowledge our sponsor, 8 Sleep. 8 Sleep makes smart mattress covers with cooling, heating, and sleep tracking capacity. Now, I've spoken before on this podcast about the critical need for us to get adequate amounts of quality sleep each and every night. Now, one of the best ways to ensure a great night's sleep is to ensure that the temperature of your sleeping environment is correct. And that's because in order to fall and stay deeply asleep, your body temperature actually has to drop about one to three degrees. And in order to wake up feeling refreshed and energized, your body temperature actually has to increase by about one to three degrees. 8 Sleep automatically regulates the temperature of your bed throughout the night according to your unique needs. Now I find that extremely useful because I like to make the bed really cool at the beginning of the night, even colder in the middle of the night and warm as I wake up. That's what gives me the most slow wave sleep and rapid eye movement sleep. And I know that because 8 Sleep has a great sleep tracker that tells me how well I've slept and the types of sleep that I'm getting throughout the night. I've been sleeping on an 8 Sleep mattress cover for four years now, and it has completely transformed and improved the quality of my sleep. Their latest model, the Pod 4 Ultra, also has snoring detection that will automatically lift your head a few degrees in order to improve your airflow and stop you from snoring. If you decide to try 8 Sleep, you have 30 days to try it at home, and you can return it if you don't like it. No questions asked, but I'm sure that you'll love it. Go to 8sleep.com/huberman to save up to $350 off your Pod 4 Ultra. 8 Sleep ships to many countries worldwide, including Mexico and the UAE. Again, that's 8sleep.com/huberman to save up to $350 off your Pod 4 Ultra. 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 photoreception. 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. Now, I talked a little bit about this 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. 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. 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. 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. These melanopsin ganglion cells have been shown to set the circadian clock and to respond best to the contrast between blue and yellow light of the sort that lands on these cells when you view the sun, when it's at 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? 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. We know time at a biological level based on where the sun is. 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. You need a lot of this light in order to trigger these melanopsin cells, which would 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. Now, here's another reason to do this. Getting two hours a day of outdoor time without sunglasses has a significant effect on reducing the probability that you will get myopia. Now, myopia or nearsightedness has to do with the way that the lens focuses light onto the retina. So remember, your eye is an optical device. 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. 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. 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. Now accommodation is our ability to accommodate to things that are 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. And you'll notice that it actually is relaxing to look at a horizon. 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. Now you might say, why are you telling me about accommodation? 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. In other words, you are not giving your lens the opportunity to flatten out and for these muscles to relieve themselves of this work, 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. 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? 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 brain stem, and allow your eyes to go into so-called panoramic vision where you're just not really focusing on anything, and then refocus on your work. 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. 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. 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. I'd like to take a quick break and acknowledge our sponsor, AG1. AG1 is a vitamin mineral probiotic drink that also contains adaptogens. I started taking AG1 way back in 2012, long before I even knew what a podcast was. I started taking it and I still take it every single day because it ensures that I meet my quota for daily vitamins and minerals and it helps make sure that I get enough prebiotics and probiotics to support my gut health. Over the past 10 years, gut health has emerged as something that we realize is important not only for the health of our digestion, but also for our immune system and for the production of neurotransmitters and neuromodulators, things like dopamine and serotonin. In other words, gut health is critical for proper brain function. Now, of course, I strive to eat healthy whole foods from unprocessed sources for the majority of my nutritional intake, but there are a number of things in AG1, including specific micronutrients that are hard or impossible to get from whole foods. So by taking AG1 daily, I get the vitamins and minerals that I need, along with the probiotics and prebiotics for gut health and in turn brain and immune system health and the adaptogens and critical micronutrients that are essential for all organs and tissues of the body. So, anytime somebody asks me if they were to only take one supplement, what that supplement should be, I always say AG1 because AG1 supports so many different systems in the brain and body that relate to our mental health, physical health and performance. If you'd like to try AG1, you can go to drinkag1.com/huberman.