Despite claims by their makers, The glasses probably don’t improve wearers’ sleep habits either, according to the study.
Blue light glasses are usually marketed as being able to filter out the potentially harmful effects of blue light from screens, such as eyestrain, dry eye, and sleep problems. Interest in blue light glasses increased during the COVID-19 pandemic as more people stayed home and looked at their computers and phones. They’re often prescribed by optometrists.
The study, published in the Cochrane Database of Systematic Reviews, looked at data collected from 17 clinical trials in six countries that recruited 619 people.
“We found there may be no short-term advantages with using blue light–filtering spectacle lenses to reduce visual fatigue associated with computer use, compared to non–blue-light–filtering lenses,” senior author Laura Downie, PhD, an associate professor of optometry and vision sciences at the University of Melbourne, said in a statement.
“It is also currently unclear whether these lenses affect vision quality or sleep-related outcomes, and no conclusions could be drawn about any potential effects on retinal health in the longer term. People should be aware of these findings when deciding whether to purchase these spectacles.”
Researchers noted that one reason the glasses don’t help is that the amount of blue light received from computer screens and other artificial sources is only about a thousandth of what people get from natural daylight. On top of that, blue light lenses usually filter out only about 10%-25% of blue light.
“Our findings do not support the prescription of blue light–filtering lenses to the general population,” Dr. Downie said.
Eye experts say people can cut down on eyestrain by simply cutting down on the amount of time they look at screens, or by taking regular breaks. To improve sleep, stop looking at screens for a few hours before bedtime.
The researchers noted limitations in their analysis. None of the studies investigated contrast sensitivity, color discrimination, discomfort glare, macular health, serum melatonin levels, or overall patient visual satisfaction.
Also, the length of the different studies varied. More studies of the use of blue light–filtering glasses is needed, the researchers said.
The study received funding from Australia’s National Health and Medical Research Council, the Public Health Agency in the United Kingdom, and Queen’s University Belfast. Two coauthors reported receiving payment from the College of Optometrists.
A version of this article first appeared on WebMD.com.