The Science of Vision, Eye Health & Seeing Better
Dr. Andrew Huberman, Professor of Neurobiology and Ophthalmology at Stanford School of Medicine, details how our visual system functions and offers over a dozen protocols to enhance and maintain eyesight, mood, sleep, and focus at any age, covering zero-cost behaviors and emerging supplements.
Deep Dive Analysis
23 Topic Outline
Introduction to the Senses, Vision, and Eye Health
How Our Eyes Work: Light Conversion to Electrical Signals
Vision as a Comparison of Reflected Light, Not Direct Seeing
Animal Vision Differences and Human Blind Spots
Subconscious Vision: Light's Impact on Mood, Metabolism, Dopamine
Sunlight Exposure for Circadian Rhythms and Overall Biology
Preventing and Offsetting Nearsightedness (Myopia) with Outdoor Time
Improving Visual and Mental Focus through Accommodation
Distance Viewing for Eye Health and Mental Relaxation
Self-Generated Optic Flow for Visual System and Mood
Using Eyelid and Eye Position to Increase Alertness
Sleeping in a Very Dark Room to Prevent Myopia
Understanding Color Vision and Colorblindness
Maintaining Sharp Vision with Daily Distance Viewing
Smooth Pursuit Visual Training for Eye Muscles
Near-Far Visual Training for Lens Accommodation
Emerging Red Light Protocol for Photoreceptor Improvement
Addressing Dry Eyes through Blinking
Lazy Eye (Amblyopia), Binocular Vision, and Brain Plasticity
Visual Hallucinations: Consequence of Under-Active Visual Brain
Snellen Chart: A Cost-Free Way to Test and Maintain Vision
Supplements and Foods for Visual Health
Importance of Blood and Oxygen for Vision Health
8 Key Concepts
Photoreceptors (Rods & Cones)
Cells in the retina that convert light information into electrical signals. Rods are primarily responsible for vision in low light conditions, while cones are specialized for bright light, daytime vision, and color perception.
Retinal Ganglion Cells
A specific class of neurons within the retina that receive processed electrical signals from photoreceptors and transmit this information from the eye to the rest of the brain for further visual processing.
Melanopsin Retinal Ganglion Cells
Intrinsically photosensitive cells in the retina that respond best to the contrast between blue and yellow light, primarily signaling time of day to the brain. They regulate sleep-wake cycles, mood, metabolism, dopamine levels, and pain threshold, operating subconsciously.
Accommodation
The dynamic process by which the eye's lens changes its shape (thickening for near objects, flattening for distant objects) to precisely focus light onto the retina. This process involves the activation of small muscles within the eye.
Smooth Pursuit
The visual system's ability to track individual objects moving continuously through space. Training this system helps maintain the conditioning and strength of the extraocular muscles and improves the brain's visual and motion tracking capabilities.
Binocular Vision
The ability of the brain to combine the slightly different visual inputs from both eyes to create a single, three-dimensional perception of depth. This process also allows the brain to fill in the natural blind spot present in each eye.
Amblyopia (Lazy Eye)
A condition resulting from an imbalance in visual input between the two eyes, often during critical developmental periods, where the brain suppresses the visual information from the weaker eye. This can lead to reduced vision in the affected eye even with corrective lenses.
Visual Hallucinations
These phenomena occur when portions of the visual system in the brain become underactive or under-stimulated. In response, the brain compensates by generating its own activity, leading to the perception of images or sensations that are not externally present.
8 Questions Answered
Our brain doesn't directly see objects; instead, it receives electrical signals from the eyes and makes a "best guess" about what's there by comparing these signals, creating our perception of the world.
Viewing sunlight for 2-10 minutes early in the day activates melanopsin retinal ganglion cells, which sets the circadian clock, improving sleep rhythms, mood, metabolism, hormone levels, and dopamine.
Yes, spending two hours a day outdoors, even with cloud cover and without sunglasses, can significantly reduce the probability of developing myopia in both children and adults.
Constantly focusing on nearby objects without breaks can strain the eye muscles and lens, potentially leading to visual defects like myopia and reducing the elasticity of the lens.
Looking up and keeping eyelids open activates brainstem circuits linked to wakefulness, increasing alertness, whereas looking down and closing eyelids promotes sleepiness.
Children sleeping in very dark rooms have a significantly lower probability of developing myopia because light exposure, especially blue light, through eyelids at night can distort lens accommodation mechanisms.
Visual hallucinations occur when parts of the brain's visual system become under-stimulated or underactive, leading to a compensatory creation of internal visual activity.
Lutein supplementation has shown benefits in offsetting age-related macular degeneration, but primarily for individuals with moderate to severe conditions, with less significant effects for those with normal or mild degeneration.
30 Actionable Insights
1. Daily Morning & Evening Light
View sunlight (even through cloud cover) for 2-10 minutes in the early morning and again in the evening to optimize sleep, mood, hormones, metabolism, pain threshold, learning, and memory.
2. Sleep in Complete Darkness
Sleep in a completely dark room (especially for children) to reduce the risk of myopia and avoid bright light exposure between 10 p.m. and 4 a.m. to prevent dopamine suppression and negative impacts on mood, learning, and immunity.
3. Two Hours Outdoor Time
Spend at least two hours outdoors daily without sunglasses (even with cloud cover) to significantly reduce the probability of developing myopia (nearsightedness) by promoting eye health.
4. Regular Eye Relaxation Breaks
Every 30 minutes of focused work, relax eye and face muscles and shift to panoramic vision. Every 90 minutes of close-up work, take 20-30 minutes of non-up-close vision (ideally outdoors looking at the horizon) to maintain eye health and prevent strain.
5. Proactive Vision Support
Train and support your eyesight, especially if young, to bolster your visual system and prevent vision loss with aging.
6. Regular Horizon Viewing
Regularly view distant horizons (beyond 20 feet, ideally further) to relax eye muscles, maintain lens elasticity, and reduce stress.
7. Elevate Computer Screen
Position computer screens at or slightly above eye level to promote wakefulness and alertness during work.
8. Look Up for Alertness
When feeling tired, look up towards the ceiling and hold for 10-15 seconds to trigger wakefulness and alertness systems in the brain.
9. Practice Smooth Pursuit
Practice smooth pursuit eye exercises (e.g., tracking a moving ball or target) for 5-10 minutes, three times a week, to maintain conditioned extraocular muscles and improve motion tracking.
10. Perform Near-Far Eye Exercises
Perform near-far accommodation exercises for 2-5 minutes every other day by focusing on an object up close, then at arm’s length, and slowly moving it in and out to train eye muscles and lens elasticity.
11. Develop Strong Binocular Vision
Young individuals should strive for strong binocular vision by engaging in both near and distant viewing, not just close-up screen time.
12. Address Eye Imbalances Early
Address strong visual imbalances between eyes (e.g., strabismus, amblyopia) as early as possible by consulting a neuro-ophthalmologist.
13. Consult Eye Specialist
Consult a good ophthalmologist (medical doctor) or optometrist for severe eye problems or to proactively address vision concerns.
14. Professional Vision Testing
Ensure vision tests are performed by a qualified professional (ophthalmologist or good optometrist) to avoid incorrect prescriptions that could weaken the visual system.
15. Monitor Vision with Snellen Chart
Place a Snellen chart at home to regularly practice and monitor your visual acuity from a set distance.
16. Red Light for Macular Health
For individuals 40+, consider flashing red light into each eye for two minutes daily before noon to potentially offset age-related macular degeneration by enhancing mitochondrial function in photoreceptors (consult a professional first).
17. Slow Blinking for Lubrication
Perform slow blinking exercises for 5-15 seconds to lubricate the eyes and maintain clear optics, especially if experiencing dry eye.
18. Balance Dominant Eye
To balance vision, cover the dominant eye for a period each day to encourage the non-dominant eye to work harder, but exercise caution, especially with children.
19. Prioritize Training Goals
For concurrent training, emphasize your primary goal (endurance or strength/hypertrophy) for a 10-12 week cycle, using a 3:2 or 4:2 ratio of primary to secondary workouts per week.
20. Incorporate Rest & Deload
Incorporate at least one complete rest day per week, and take 5-7 days completely off after a 10-12 week training cycle to prevent injury and ensure progress.
21. Incremental Training Progression
Begin with the minimum number of sets for a new training protocol (e.g., 2-3 sets) and incrementally add sets each week to progress safely.
22. Engage in Optic Flow
Engage in self-generated optic flow activities (e.g., walking, biking) to benefit the visual system and mood-regulating brain systems.
23. Cardiovascular Health for Vision
Maintain a healthy cardiovascular system through regular endurance and strength training to indirectly support eye and brain health by ensuring adequate blood flow and nutrients.
24. Consume Vitamin A-Rich Foods
Consume raw or near-raw dark leafy vegetables and carrots (rich in Vitamin A) to support vision.
25. Daily Nutritional Support
Consider taking an all-in-one vitamin-mineral probiotic drink once or twice a day to cover basic nutritional needs, address deficiencies, and support microbiome health.
26. Morning & Exercise Electrolytes
Drink one packet of electrolyte mix in 16-32 oz of water first thing in the morning and during physical exercise for proper hydration and electrolyte balance.
27. Utilize Meditation App
Use a meditation app that offers various durations and types of meditation, mindfulness, yoga nidra, or NSDR sessions to restore cognitive and physical energy.
28. Lutein for Macular Degeneration
If experiencing moderate to severe age-related macular degeneration, consult a physician about supplementing with lutein to potentially offset vision loss.
29. Zeaxanthin & Astaxanthin for Aging Eyes
Consider supplementing with Zeaxanthin and Astaxanthin to potentially offset age-related vision disruption and increase ocular blood flow, after consulting a professional.
30. Idebenone for Optic Neuropathies
For Leber’s congenital eye disease or optic neuropathies, research Idebenone on examine.com and consult a physician about its potential benefits.
5 Key Quotes
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.
Andrew Huberman
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.
Andrew Huberman
If you can hold visual focus, you can hold mental focus, cognitive focus, but holding visual focus is challenging.
Andrew Huberman
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.
Andrew Huberman
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.
Andrew Huberman
13 Protocols
Protocol for Better Biology & Psychology (Sunlight Viewing)
Andrew Huberman- View sunlight for 2 to 10 minutes in the early part of the day when the sun is low in the sky.
- Repeat the same in the evening.
- Do this without sunglasses, even through cloud cover.
Protocol to Prevent & Offset Near-Sightedness (Myopia)
Andrew Huberman- Spend 2 hours a day outdoors.
- Do this without sunglasses, even if there's cloud cover.
- This includes reading or other activities outdoors.
Protocol for Improving Visual & Mental Focus (Distance Viewing)
Andrew Huberman- For every 90 minutes of 'close viewing' (screens, reading), take a break.
- Spend at least 20, preferably 30, minutes in non-up-close vision.
- Ideally, go outside or look out a window at a distance (horizon).
- Let your eyes relax into panoramic vision.
Protocol for Self-Generated Optic Flow
Andrew Huberman- Move through space daily (walking, biking, swimming).
- Ensure it's self-generated motion (not driving).
- Allow visual images to pass by on your eyes.
Protocol to Be More Alert (Eye Position)
Andrew Huberman- If feeling tired, look up towards the ceiling.
- Raise your eyes and try to hold that position for 10 to 15 seconds.
- Position computer screens at or above eye level.
Protocol to Prevent Myopia (Dark Room Sleep)
Andrew Huberman- Sleep in a completely black or very dark room.
- Wean children off nightlights to promote darker sleep environments.
Protocol for Keeping Vision Sharp (Distance Viewing Every Day)
Andrew Huberman- Spend at least 10 minutes a day total viewing things off in the distance.
- Aim to see a horizon, well over half a mile or more away.
- Allow your eyes to relax and expand into panoramic vision.
Protocol for Smooth Pursuit Visual Training
Andrew Huberman- Visually track a moving object (e.g., a ball on a screen, a pen, or live sports).
- Practice for 5 to 10 minutes, three times a week.
- Use stimuli that move smoothly, sometimes in an infinity symbol, changing speed, or dilating/contracting.
Protocol for Near-Far Visual Training
Andrew Huberman- Look at an object up close for a few minutes, feeling the strain of accommodation.
- Slowly move the object to arm's length and focus on it for 5-20 seconds, feeling the relaxation.
- Move it past the relaxation point, maintaining focus.
- Repeat this process for 2-3 minutes, maybe every other day.
Protocol for Red Light to Improve Photoreceptors & Vision
Andrew Huberman- Flash red light into one eye for a couple of minutes a day.
- Repeat for the other eye.
- Do this early in the day (before noontime).
- This is for individuals 40 years or older to offset age-related macular degeneration.
Protocol for Dry Eyes (Blinking)
Andrew Huberman- Perform slow blinks (e.g., one blink every second or two).
- Continue for 5 to 15 seconds.
- This lubricates the eyes and clears the corneal surface.
Protocol for Lazy Eye (Amblyopia) & Binocular Vision
Andrew Huberman- If you have a weaker eye, cover the dominant (stronger) eye.
- Perform near-far training with the weaker eye.
- This forces the weaker eye to work harder and helps balance visual input.
Protocol for Vision Testing & Maintenance (Snellen Chart)
Andrew Huberman- Place a Snellen chart in your home or office.
- Practice reading the letters from a particular distance.
- Regularly check your vision performance.