Do Blue Light Glasses Work? What the Research Shows

For eye strain, the research so far says they may not help. A 2023 Cochrane review of 17 randomized trials found that blue-light filtering glasses may not reduce eye strain from computer use compared with ordinary clear lenses, over the short periods studied. Trials on sleep gave mixed results, and none of the 17 trials measured whether the lenses protect the macula, the part of the eye that controls sharp, straight-ahead vision. The American Optometric Association lists these possible causes of screen symptoms: poor lighting, glare on the screen, the wrong viewing distance, poor posture and uncorrected vision problems.

Key takeaways

A 2023 review of 17 short trials found blue light glasses may not ease eye strain from computer use any more than ordinary clear lenses.
Sleep trials gave mixed results, and none of the 17 trials measured whether the lenses protect the macula, which controls sharp, straight-ahead vision.
For tired eyes at a screen, look 20 feet away for 20 seconds every 20 minutes, keep the screen 20 to 28 inches away and blink often.
If screen symptoms continue after those changes, an eye exam can check your focusing, eye alignment and dry eye.

What are blue light glasses supposed to do?

Blue light glasses, also called blue-light filtering or blue-light blocking lenses, filter ultraviolet radiation and part of the short-wavelength visible light, the blue end of the spectrum, before it reaches your eyes. How much of that blue light a lens filters varies from one product to the next.

They're sold on three claims: easier vision on digital devices, protection for the retina and better sleep. The Cochrane review looked for trial evidence on each one.

Screens aren't the only source of blue light. The AOA lists LED and fluorescent lighting along with monitors, tablets and phones.

Do blue light glasses help with eye strain?

The trials suggest they may not. Comparing blue-light filtering lenses with ordinary clear lenses, the Cochrane reviewers found there may be no difference in visual fatigue, and probably little or no difference in how sharply people could see.

Those trials were small and short. Each of the 17 had between 5 and 156 participants, and people were followed for anywhere from less than a day to five weeks.

Dry eye can be part of the problem too. Spending a lot of time on a computer, tablet or phone can cause dry eye, and dryness needs its own care, which our screens and dry eye page explains.

Can blue light glasses help you sleep?

The evidence is mixed. Six trials with 148 participants looked at sleep: three found better sleep scores with blue-light filtering lenses, and three found no significant difference.

The reviewers rated that evidence very low certainty and called the effect on sleep indeterminate. Across the review, the people studied ranged from healthy adults to people with mental health and sleep disorders, and none of the trials measured melatonin levels in the blood, so the review couldn't say whether the lenses change levels of the sleep hormone.

The idea comes from how the body clock works. In the evening, your master clock tells the brain to make more melatonin, the hormone that causes sleepiness, and it controls melatonin based on the amount of light your eyes receive. Light from electronic devices at night can confuse that clock.

For better sleep, the CDC suggests turning off electronic devices at least 30 minutes before bedtime.

Do blue light glasses protect your eyes from damage?

The trials haven't shown that they do. None of the 17 trials in the Cochrane review measured macular health, so the review couldn't tell whether the lenses protect the retina.

The American Optometric Association takes a more cautious view of blue light itself. It says blue light from LED and fluorescent lighting, monitors, tablets and phones can negatively affect vision over the long term, and that special lens tints and coatings can reduce its harmful impact.

None of the trials in the review tested that long-term question. The Cochrane authors say high-quality trials are still needed to define the effects of blue-light filtering lenses on vision, macular health and sleep.

What helps tired eyes at a screen?

Changes to how you use the screen, and glasses that suit the distance. The American Optometric Association recommends these steps:

Follow the 20-20-20 rule: every 20 minutes, look at something 20 feet away for 20 seconds. After two hours of continuous computer use, rest your eyes for 15 minutes.
Place the screen 20 to 28 inches from your eyes, with its center 15 to 20 degrees below eye level, and position it to avoid glare from overhead lights and windows.
Blink often, which lowers the chance of dry eye at the computer.
Wear lenses that suit the screen distance. Glasses or contacts prescribed for general use may not be adequate for computer work.

If symptoms continue after those changes, our computer vision syndrome exam looks at focusing, eye alignment and dry eye.

Are blue light glasses worth buying?

The evidence so far doesn't support buying them for eye strain or eye protection, and the results for sleep are mixed. If you already own a pair and like them, wearing them is your call; just don't count on them to prevent eye strain.

Side effects in the trials were infrequent but included headache, discomfort wearing the glasses, increased depressive symptoms and lower mood.

Should kids wear blue light glasses?

Not to slow myopia: blue-light filters aren't a myopia control treatment, as our page on outdoor time, screens and myopia explains. The Cochrane review covered only adults, so its findings don't tell us how the lenses work for children.

Children use their eyes at every distance during the school day, from the board to the computer to a book, and because their vision can change often, the AOA recommends an eye exam every year through the school years.

How we check screen strain at Cohenmehr Optometry

When screens leave your eyes tired, dry or blurry, a comprehensive exam, part of our computer vision syndrome care, evaluates your visual system, focusing and eye alignment to find the underlying cause.

Treatment from our Los Angeles eye doctors can include customized computer or office lenses, contact lens changes, adjustments to your screen setup and care for the dry eye that often comes with screen use. If a small misalignment between where your eyes aim up close and where they rest is part of the problem, Neurolens lenses with a contoured prism are often used to relieve that strain.

Questions patients ask

Are computer glasses the same as blue light glasses?

No. Computer glasses carry a prescription chosen for your screen distance, about 20 to 30 inches away, because glasses made for distance or reading may not give efficient vision there. Blue light glasses filter part of the light that reaches your eyes. A pair can have both a computer prescription and a blue-light filter, but they're separate features.

Do blue light glasses protect against UV?

They're meant to: the Cochrane review describes blue-light filtering lenses as filtering ultraviolet radiation along with part of the blue light. For time outdoors, though, wear sunglasses that block at least 99% of UV rays, year-round, because everyone is at risk for eye damage from the sun. Our UV protection and sunglasses guide covers how to choose them.

How much screen time is too much for your eyes?

Even two hours a day can be enough to cause symptoms: the American Optometric Association reports that as little as two hours of screen exposure per day can bring on digital eye strain. Almost one in three people in the U.S. spend seven or more hours a day on screens. For long days, the AOA recommends a 15-minute break after two hours of device use and the 20-20-20 rule.

How can you lower your risk of macular degeneration?

Research shows you may be able to lower your risk of age-related macular degeneration (AMD) by quitting smoking or never starting, getting regular physical activity, keeping blood pressure and cholesterol healthy, and eating healthy foods, including leafy green vegetables and fish. Regular eye exams matter too if you're at risk because of age or family history, since early AMD has no symptoms; see our page on macular degeneration care.

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Written by

Dr. Bijan Cohenmehr, OD

Founder of Cohenmehr Optometry, in practice for over 40 years. He leads the practice’s dry eye care and myopia management. A graduate of SUNY College of Optometry.

About Dr. Bijan →

Do Blue Light Glasses Work? What the Evidence Shows