Do blue-light glasses work? What the research shows

Most people spend hours a day looking at screens, and glasses that filter blue light have become a popular add-on, sold to ease tired eyes, protect the retina and help people sleep. Some come with a yellow or amber tint; others look almost clear.

The best summary of the evidence, a 2023 review in the Cochrane Database of Systematic Reviews, found that blue-light glasses probably do little for eye strain or sharpness of vision. Their effect on sleep is uncertain, with small trials pointing in different directions, and no trial has tested claims about protecting the retina.

What blue-light glasses do

The Cochrane review explains that blue-light filtering lenses filter ultraviolet radiation and varying portions of short-wavelength visible light from reaching the eye. Short-wavelength visible light is what people call blue light. Screens give off some of it, and so does the sun.

The marketing claims fall into three groups: better visual comfort with digital devices, protection of the retina, and better sleep. The review set out to test each of them against trials that compared blue-light filtering lenses with ordinary lenses.

What the Cochrane review found for eye strain and vision

The review found 17 randomized trials, with between five and 156 participants each and follow-up ranging from less than a day to five weeks. None had a low risk of bias across all the areas reviewers check, and the data were too varied to combine in a meta-analysis.

For eye strain, the authors concluded that blue-light filtering lenses may not attenuate symptoms of eye strain with computer use, meaning they may not ease it, at least over short periods. For sharpness of vision, there is probably little or no effect. No trial measured effects on the macula, the part of the retina used for detailed central vision, so claims about protecting it remain untested.

Side effects were reported inconsistently. Those that were reported were infrequent but included headache, discomfort wearing the glasses, lower mood and increased depressive symptoms.

What studies show about blue-light glasses and sleep

The idea behind the sleep claim is reasonable. The American Academy of Ophthalmology notes that blue light does affect the body’s circadian rhythm, our natural wake and sleep cycle, and that too much at night can make it harder to fall asleep. Blue light may affect sleep by suppressing melatonin, a hormone that rises in the evening, according to researchers who tested amber lenses in a trial published in the Journal of Psychiatric Research.

That small crossover trial, meaning each person tried both kinds of lens in turn, gave 14 people with insomnia symptoms amber lenses or clear lenses to wear for two hours before bed for a week each. Their insomnia scores improved with the amber lenses. But across the six sleep trials in the Cochrane review, with 148 participants in total, three found better sleep scores and three found no difference, in very different groups of people. The review rated the certainty as very low.

An earlier review, published in 2017, reached a similar view, finding a lack of high quality evidence to support blue-light blocking lenses for the general population to improve vision or sleep, ease eye fatigue or protect the macula.

What eye doctors say about blue light from screens

The American Academy of Ophthalmology states that there is no scientific evidence that blue light from digital devices causes damage to your eye. It attributes the discomfort many people feel after screen use to digital eye strain, partly because people blink less while looking at screens.

The academy does not recommend any special blue light-blocking eyewear for computer use. It points instead to regular breaks, such as its “20-20-20” rule of looking at something 20 feet away for 20 seconds every 20 minutes. For sleep, an academy spokesperson recommends limiting screen time in the two to three hours before bed.

Why the blue-light research is hard to interpret

Most trials were small and short, and they tested many different lenses, from strongly amber tints to nearly clear coatings. Participants ranged from healthy adults to people with sleep or mental health conditions. Tinted lenses are also hard to disguise, so people often knew which glasses they had, which can sway self-reported outcomes such as eye strain and sleep quality.

What the blue-light research cannot tell us yet

No trial has followed people long enough to test whether blue-light filtering lenses protect the retina over years. The sleep findings leave open whether specific groups, such as people with insomnia, benefit when the general population does not. The Cochrane authors call for larger, higher-quality trials.

What the blue-light evidence adds up to

Blue-light glasses probably do little for eye strain or vision in the short term, and there is no trial evidence that they protect eye health. Their effect on sleep is uncertain, with small, mixed trials.

The American Academy of Ophthalmology does not recommend them for computer use and attributes screen discomfort mainly to eye strain from blinking less. Whether any product suits one person depends on what problem they are trying to address.