Blue-Light Glasses

Skip clear blue-light glasses. For screen strain, take breaks and blink; for sleep, dim the lights in the evening first, and if you want glasses, only a deep orange lens rated to block most blue light, worn in the last hour or two before bed, has a physiological basis.

Screens don't damage your eyes

Blue light is the short-wavelength end of visible light. A phone or tablet at full brightness gives roughly 0.1–0.4% of the international safety limit for blue light, against about 10% for looking at a blue sky on a sunny day. A screen delivers something on the order of one percent of the blue light of open sky, and typical blue-blocking glasses filter only a fraction of that.^[1]

The American Academy of Ophthalmology says there is "no scientific evidence that blue light from digital devices causes damage to your eye", and "the Academy does not recommend any special blue light-blocking eyewear for computer use", while noting that blue light's effects are still being researched.^[2]

What the trials show

The strongest single source is the 2023 Cochrane review of blue-light-filtering lenses: 17 randomised trials of five to 156 participants each, followed for less than a day to five weeks. It found the lenses probably make little or no difference to sharpness of vision and may make no difference to eye fatigue. It found no randomised evidence at all on macular health, pooled nothing, and rated no outcome at high certainty.^[3] Much screen discomfort comes from blinking less often and less completely while you stare at a display, which is what screen breaks and the 20-20-20 rule are meant to counter; that is covered on Vision.

Sleep: clear lenses no, deep orange lenses maybe

On sleep, the Cochrane review could not reach a conclusion: the six trials in 148 people that measured it split three to three, at very low certainty.^[4] A 2025 pooling of three double-masked trials, 49 people in all, found no significant effect on sleep measured with wrist trackers. Time to fall asleep fell by about five minutes, an estimate so imprecise that the glasses could equally have made it ten minutes slower, so this is an underpowered null rather than proof the glasses do nothing.^[5]

Part of the problem is that most products are far too weak to matter. A test of 26 commercial models set a bar for a true blue blocker on a new measure of how much body-clock-setting ("melanopic") light a lens removes. The products ranged from 0.01 to 3.43 against a bar of 1.0, and the clear and near-clear lenses sold in most optical shops for screen use fell below it. Under office LED lighting, only about 31% of the filters tested cut that light enough to reach the recommended evening level. In 16 field studies of glasses that did clear the bar (dark orange lenses), worn in the hours before bed, at least one sleep or body-clock measure improved every time. Two of the paper's five authors work for a blue-light-filtering software company.^[6]

Even the strong lenses are a weaker lever than turning the lights down. Evening light and the body clock are covered in Light at night.

What to do

1. Don't buy clear blue-light glasses for eye protection, eye strain or sleep.
2. For screen discomfort, take regular breaks, blink fully, adjust brightness and text size, and get an eye exam if it persists.
3. For sleep, get morning daylight and dim the room in the evening. If you still want glasses, choose a deep orange lens rated to block most blue light, and wear it only in the last hour or two before bed. For insomnia itself, sleep habits and a check for sleep-disordered breathing come before any optical filter.

Further reading

• Singh S et al. Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults. Cochrane Database of Systematic Reviews 2023.^[7]
• Luna-Rangel FA et al. Efficacy of blue-light blocking glasses on actigraphic sleep outcomes: a systematic review and meta-analysis of randomized controlled crossover trials. Frontiers in Neurology 2025.^[8]
• Glickman GL et al. Optimizing the potential utility of blue-blocking glasses for sleep and circadian health. Translational Vision Science & Technology 2025.^[9]
• Wong NA et al. A review of the current state of research on artificial blue light safety as it applies to digital devices. Heliyon 2022.^[10]