Vision experts generally don't recommend blue-light-blocking glasses because there's no scientific evidence that the light from computer screens damages eyes.

People with blue eyes appear to be at elevated risk of developing macular degeneration, perhaps because more light can penetrate their eyes.

The design of a psychiatric ward in Norway aims to integrate more circadian rhythm-friendly lights as part of its treatment protocols for conditions including psychosis, severe depression, and more.

Eclipse glasses protect the eyes from overexposure to the sun's ultraviolet, blue, and infrared light, as a person's instinct to look away from the sun is diminished when it's partly blocked.

High-powered red light therapy—delivered directly to nerve fibers via a fiber optic needle—has been used in recent experimental research to suppress pain.

Because the retina lacks pain receptors, during a solar eclipse, those watching without protective eyewear may suffer from permanent damage without realizing it.

Using brain implants to restore vision

Several companies are attempting to create brain-computer interfaces that skip over retinas and optic nerves to allow visual input to go straight to the brain, potentially restoring some sight to the blind. Clinical trial findings suggest restored sight is sparse and manifests differently than a sighted person might expect, appearing as specks of "light" clusters called phosphenes to help differentiate one's surroundings.

There is a template for how to live a better, healthier day, and it includes a digital sunset

Science suggests that early-morning exercise, later-morning peak work or social time, consistent exercise, and a "digital sunset"—starting to turn down the lights in the evening and avoid screens—are important for circadian health.

Certain visible light therapies, when applied at specific intensities, can be used to treat skin conditions, including acne.

Limited battery life and increasing discomfort prevent extensive use of mixed reality headsets

Spending 24 hours wearing Apple's Vision Pro highlights some of the challenges facing MR technology, which are compounded by an increasing number of bugs when software is run in nonideal conditions. However, practical and entertainment benefits include placing multiple midair timers when cooking and experiencing immersive multimedia, such as astronomical flythroughs.

See how cataracts—a leading cause of vision loss globally—form and how sound waves are often used to help remove them.

Disconnecting from technology can be made easier by turning off notifications, making nonessential apps and devices harder to access, and opting for 'dumb' devices, such as a film camera.

What did people do before eyeglasses were invented?

An estimated two-thirds of the world's adults use a form of prescription glasses or contacts, proof spectacles were a godsend when they were invented in 1286 CE. But what did people do before that? Different tools were used for distinct vision problems, but some would use magnifying lenses, clear emeralds, and more. Watch this video for a historical explanation.

Studies suggest when you sleep is as important as how much you get.

One theory claims the retinae of SAD patients may fail to adjust to less light in winter

Most people’s eyes become more sensitive to light in the winter months, but some do not. This failure to adjust causes ripple effects on those individuals’ biological clocks. This Ted-ED video provides a clear, brief, narrative explanation of the condition in six minutes.

This 1440 Original video dives into what the science says about phototherapy and its various potential applications.

Corrective vision technologies rely on the bending of light waves

When focusing on an object, muscles change the shape of the lens, which refracts incoming light such that it focuses at the retina. If the cornea is unable to bend light correctly, lenses or contact lenses can provide supplemental refraction to ensure a focused image is produced.

Temperature and certain medications can also affect your circadian rhythms

Although light and dark have the largest influence on circadian rhythms, temperature, stress, and certain medications are among the factors that also play a role. Persistent trouble sleeping or staying asleep may signal it’s time to see your doctor to get a better sleep-wake schedule.

Emulating Earth’s light-dark cycle is important for astronaut health and safety

Astronauts aboard the International Space Station experience 16 daily sunrises, but scientists have learned to try to promote circadian rhythms by phasing through several light settings aboard the ISS to improve astronauts’ sleep and productivity.

Proteins with limited light sensitivity prevent humans from seeing all types of light

Specialized photoreceptor cells in the retina called cones each possess photopigments that activate when exposed to three ranges of visible light. Other forms of electromagnetic radiation outside the activation range do not generate signals for processing in the brain, thereby limiting average human vision to approximately 10 million colors.

Light pollution is giving oysters insomnia

Oysters, bivalve mollusks that have light-detecting cells along their skin, can't sleep with all this artificial light. According to a 2022 study, oysters' sleep cycles are disturbed by light dimmer than that provided by the full moon. As with humans, it's possible that these bouts of insomnia could have adverse health effects and contribute to the development of disease over time.

Watch how doctors examine leprosy patients for signs of vision impairment

Clinicians must screen for symptoms of eye and vision damage in leprosy patients, including loss of sensation, reduced blink reflex, and inability to close or keep the eyes closed.

Scientists create contact lenses that give you infrared vision

Scientists have created lenses that use nanoparticles to convert infrared light into visible light, allowing human eyes to observe previously invisible parts of the electromagnetic spectrum. This technology may help colorblind individuals by converting colors they cannot see into wavelengths they can.

Age-related macular degeneration is the primary cause of blindness in older Americans.

Jaundice, which can make the skin and eyes appear yellow, is a buildup of bilirubin, a waste product that forms when old red blood cells break down.

Our phones can provide a dopamine hit because of our positive associations with them, which feeds into what some psychologists call social media addiction.

Most things you would get tested for at the doctor’s office are influenced by circadian rhythm

In this video, a Salk Institute Researcher offers daily habit tips focused on aligning with your circadian rhythms. She notes heart rate and blood pressure are highest in the afternoon, for example, and there’s a triglyceride peak in the morning. Generally, she says, it’s a good idea to schedule your doctor’s checkups at the same time of day each year so there’s consistency across your data.

Early testing of the US Army's mixed reality headsets made soldiers perform worse

Soldiers involved in testing the Integrated Visual Augmentation System reported headaches, nausea, limited peripheral vision, and concerns about security due to the display backlighting, which could be viewed from hundreds of meters away. The difficulties led the Department of Defense to transfer the program's contract from Microsoft to Anduril Industries.

Vitamins can slow macular degeneration

Research published in 2022 affirmed that vitamin formulations containing vitamins C and E, copper, zinc, lutein, and zeaxanthin—but no beta carotene—can enhance eye health and slow the progression of macular degeneration.

Artificial lighting and modern practices like working late are linked with sleep shifts

An analysis of five adults participating in a German reality program that tasked them with living in a Stone-Age-like settlement for 2.5 months, provided some insights into how modern conditions may have shifted our circadian rhythms. The participants slept about 90 minutes more under these conditions, and went to bed earlier and rose earlier, raising questions about how circadian rhythms, sleep, and sleep quality are affected by modern lifestyles.

There is a best way to wake up—but not a best time

Sleep and circadian rhythm researchers say that waking up at a consistent time each day—even on weekends—and viewing morning sunlight are the best ways to keep body functions running at their peak. (Some users may encounter a paywall.)

The science of optical illusions

The human brain has developed cognitive shortcuts to help us navigate in a world where our visual senses are constantly bombarded of information. But these shortcuts can also be exploited, tricking the brain into telling us something is happening when it really isn't. This short video unpacks the neuroscience behind some of the most common (but perplexing) optical illusions.

Why are kids increasingly diagnosed with myopia?

According to the World Health Organization, 40% of the world will have myopia—nearsightedness—by 2030. This NPR podcast episode details why people are being diagnosed with myopia at increasingly younger ages. Early onset myopia can lead to...

Lack of sunlight during Arctic winters can fuel a winter slump and a circadian disconnect.

Ending daylight saving time may prevent as many as 300,000 strokes annually

Changing clocks twice a year disrupts circadian rhythms, which last an average of 24 hours and 12 minutes. Studies have shown that permanent daylight saving time provides fewer health benefits than standard time.

Obsessing over sleep metrics leads to worse sleep quality

Over one-third of Americans have used wearable technology to track their sleep, and the anxiety over having perfect sleep data, or orthosomnia, has made getting a good night's sleep more difficult. Experts agree that most devices cannot correctly assess sleep details, making the data unreliable.

The origin of LASIK eye surgery, from a lab incident to federal funding and widespread use

After a University of Michigan engineering student suffered retinal burns from an ultrashort pulse laser, researchers realized it could be used to reshape the cornea and improve a person's vision with greater precision than a scalpel and earlier laser technologies. Agencies, including the National Science Foundation, the National Institutes of Health, and the Department of Energy, provided funding to develop and commercialize the procedure.

Unlike America's recommendations, Australian authorities don't encourage routine sunscreen use for darker skin tones—reasoning that melanoma risk is low, and it's better to get UV exposure to help the body naturally produce vitamin D.

External factors, not aging itself, lead to sleep loss in older adults

Though it is often believed that people need less sleep as they age, the recommended sleep guidelines for all adult age groups are almost identical. However, factors such as medication use, lack of physical activity, and loneliness can lead to sleep problems, and thereby lead older people to believe that they actually need less sleep than they do.

How dreams affect your memory

In 1999, scientists conducted a study in which participants were asked to recall images flashed before them for milliseconds. They found that participants who slept before recalling the information performed better than those who had been asked to recall the same information that same day. This was some of the earliest convincing evidence of how crucial sleep is for learning and memory, findings that current research continues to strengthen.

Some sounds that have been shown to affect mood and noise have been given color names, such as brown, pink, and green noise, corresponding their frequencies to those of light.

Changes in vision or eye pain can be early MS symptoms

This occurs due to myelin degradation around the optic nerve, impairing its ability to transmit visual information to the brain. Individuals may especially experience eye symptoms after exercising or taking a hot shower because boosted body temperatures slow down nerve function in nerves already damaged by MS.

The side effects of falling back and springing forward

Daylight saving time can interfere with a person’s sleep schedule, but it also has been linked to increased rates of depression, heart attack, stroke, cancer, and car accidents. UT Southwestern’s Dr. Joseph Takahashi explains why the time change is bad for your brain and health.

Olympians view sleep as a performance tool, prioritizing routine and environment

Elite athletes emphasize consistent sleep routines, dark and cool environments, the well-placed nap, and tools like eye masks, white noise machines, and supplements like melatonin (particularly for jet lag). This priority belies a core principle: recovery and performance are inseparable. Read more ways Olympians "sleepmaxx" here.

Melanin and light scattering contribute to different eye colors

Brown eyes have high melanin, while blue eyes have low melanin. Multiple genes contribute to eye color, which can change over time due to melanin buildup. Hazel eyes can shift color depending on ambient light.

Bright light therapy involves basking in 10,000 lux of light for 30 minutes each morning

Nothing is better than going outside and soaking up real sunlight. However, this is harder in winter, especially in very cold and cloudy regions. SAD lamps are designed to project 10,000 lux—a unit of illuminance, or how much light actually hits a surface (rather than how much is produced, like watts). This video discusses product options and practical considerations.

Where did artful screen savers go? A history

Early on in the personal computer days, users and engineers realized screens could be damaged if the same image—of a button, a logo, or a navigation bar—stays static for too long. To preserve the screen, developers deployed screen savers—automatic reductions in the light intensity, or regularly changing patterns on the screen. These artful screen savers had a heyday in the 1990s, but have since lost popularity to the simple black screen. Read the history here.

Eliminating distractions is essential to improving one's attention span

Setting a baseline, removing distractions, establishing focus rituals, taking breaks, and finding purpose in your task are five science-backed practices that can help address a short attention span. Bestselling author Daniel Pink breaks down how to approach each part of the plan and introduce these habits to your life today.

Vertigo may be reduced by retraining your brain with visual fixation

In this video podcast neuroscientist Andrew Huberman describes one way to help alleviate dizziness and motion sickness symptoms. He suggests visual anchoring—fixating your vision on a point several feet away and moving closer to it, if possible, or fixating your vision on your extended finger and slowly moving it toward your nose and away again.

Medical professionals have experimented with using mixed reality headsets

Devices like the Apple Vision Pro have helped doctors develop surgical plans for hip and knee replacements using software that provides 3D models and other tools. Virtual screens displayed by mixed reality devices can provide information related to surgical progress, a patient's vitals, and more.

The brain will attempt to rest itself in periods of chronic sleep deprivation

Skimping on sleep lengthens reaction times and blunts decision-making skills. At a certain point, the brain will try to sneak sleep where it can, shifting sections offline even as you remain awake. Going without sleep raises blood pressure, undermines the immune system, and increases one's risk of dementia.