Blue light glasses have 'virtually no effect' on eye strain caused by staring at a screen, new study finds
Blue light glasses have been a buzzy eyewear item for years. The glasses are designed to filter out blue light — which is commonly emitted from screens — and many fans claim that they can reduce the risk of eyestrain and migraine. Some say these glasses may even improve your sleep.
But for all of the hype surrounding them, blue light glasses have been controversial, with many doctors arguing that they don’t live up to the claims. Now there’s a new study that suggests these glasses don’t do much of anything. Here’s what you need to know.
What the study says
The study found that, when compared to regular lenses, blue light glasses don't help with visual performance, protect eyes or boost sleep quality.
What are the key findings?
The study, which was published in the Cochrane Database of Systematic Reviews, analyzed data from 17 randomized, controlled trials where blue-light-filtering lenses were compared with non-blue-light-filtering lenses in adults. Sample sizes for each trial ranged from five to 156 participants, with follow-up periods between less than a day and five weeks.
The researchers analyzed the data for factors such as visual performance, visual fatigue, eye strain and sleep quality and found that blue light glasses didn’t do much. The researchers also found that the bulk of the studies had a high risk of bias (i.e., there were flaws in the design or analysis, and that the results may not be accurate).
The study’s conclusion broke it all down. “This systematic review found that blue-light-filtering spectacle lenses may not attenuate symptoms of eye strain with computer use, over a short-term follow-up period, compared to non-blue-light-filtering lenses,” the researchers wrote. “Based on the current best available evidence, there is probably little or no effect of blue-light-filtering lenses on best-corrected visual acuity [the ability to see shapes and details at a distance] compared with non-blue-light-filtering lenses."
The researchers noted that potential effects on sleep quality were “indeterminate” and that there was “no evidence” to support other claims surrounding blue light glasses, including that they help reduce glare, improve eye health, influence melatonin levels or help people see better.
Basically, there was no data to suggest that blue light glasses are effective.
“The prescription of blue-light-filtering spectacle lenses began increasing in popularity in the 2000s, based on a suggestion that these lenses might protect the eyes from any potential adverse effects of blue light,” study co-author Laura Downie, an associate professor in the department of optometry and vision sciences at the University of Melbourne, tells Yahoo Life. “However, whether blue light emitted from computer screens causes eye strain remains controversial.”
What experts think
Dr. Vivian Shibayama, an optometrist at UCLA Health, tells Yahoo Life that she's not surprised by the findings. “There’s no evidence that they help,” she says.
Phillip Yuhas, assistant professor at the Ohio State University College of Optometry, tells Yahoo Life that he’s also not shocked at the conclusion. "Everything so far in the literature suggests weak — at best — evidence that blue light glasses do anything," he says. "Most studies suggest virtually no effect."
Dr. Mina Massaro-Giordano, co-director of the Penn Dry Eye and Ocular Surface Center and a professor of clinical ophthalmology at the University of Pennsylvania agrees. “There has never been great science in terms of blue light blocking,” Massaro-Giordano tells Yahoo Life. “We as ophthalmologists do not say, ‘You should be getting blue-light-blocking glasses.’”
The idea of blue light glasses isn’t entirely out of left field, though, Downie says. “It is important to recognize that blue light can regulate normal physiological functions, such as the circadian rhythm," she says. "But, concerns have also been raised about the potential for blue light to pose a hazard to the eye. This is largely based on results from animal studies, and cell culture experiments in the laboratory that have shown that high-intensity, short-wavelength visible light exposure can induce retinal-cell damage."
But a direct link between blue light and eye health in humans is "unproven" and suggests that the conclusions from these animal studies can apply to people “remains questionable,” Downie says.
“The light emitted from modern lighting sources, including computer screens, falls well within safe levels and thus is considered not to pose any significant risk to eye health,” she says, noting that the biggest source of blue light that people are exposed to is natural sunlight.
As for the interest generated by these glasses, Yuhas says a lot of it comes down to marketing. “Lens companies and practitioners can sell blue light products for a little more,” he says. “There’s a financial advantage to hype the blue light capability of products.’
Why it matters
Blue light glasses typically cost more than those with regular lenses and you can end up spending more for a product that doesn’t live up to its claims. Shibayama says that “it doesn’t hurt” (other than your wallet) to use blue light products, but there are other things you can do to improve your eye health.
“I ask patients to use night mode on their devices, which reduces the blue light,” Shibayama says. Taking breaks from screens by following the 20/20/20 rule (every 20 minutes look 20 feet away for 20 seconds) can also help with eye strain, she says.
If patients are interested in blue light glasses, Massaro-Giordano says she tells them that there’s likely no harm to it. “Some people feel less eye strain,” she says. “Could it be a placebo? I don't know.”
Yuhas says that he tells his patients interested in blue light glasses that there is “little evidence that they will do anything to help their visual comfort or performance.” He adds, “I tell them that if they like the slight yellow tint it gives, then God bless them. But they should temper their expectations.”
