Glasses that block blue light probably do not improve the health of your eyes or the quality of your sleep, according to a recent scientific review.
Researchers at the University of Melbourne in Australia reviewed data from 17 randomized controlled trials around the world and found no strong evidence that spectacles made to block blue light could:
- Protect the retina.
- Reduce eye strain.
- Promote better sleep.
The review was published in the Cochrane Database of Systematic Reviews. Cochrane is a nonprofit that analyzes and compiles medical data from high-quality scientific sources to help consumers make better health decisions.
In a summary of the findings, review co-author Laura Downie — head of the Downie Laboratory: Anterior Eye, Clinical Trials and Research Translation Unit at the University of Melbourne — says:
“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. 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.”
Downie notes that the short follow-up period in most of the studies the researchers reviewed prevented them from evaluating potential longer-term outcomes.
Still, she believes that people should know about the review findings before purchasing glasses that block blue light.
Filtering out blue light has been all the rage in recent years. A 2018 Australian survey of 327 optometrists found that 75% have prescribed lenses that block blue light despite limited evidence in support of the lenses.
Downie says the researchers’ findings “do not support the prescription of blue-light filtering lenses to the general population.”
In the summary of the researchers’ findings, Sumeer Singh, a postdoctoral research fellow in the Downie Laboratory and a co-author of the review, noted that the blue light the average person receives from artificial sources like computer screens is just “a thousandth of what we get from natural daylight.” He continues:
“It’s also worth bearing in mind that blue-light filtering lenses typically filter out about 10-25% of blue light, depending on the specific product. Filtering out higher levels of blue light would require the lenses to have an obvious amber tint, which would have a substantial effect on colour perception.”
On a positive note, the researchers also did not find strong evidence that wearing glasses that block blue light causes adverse side effects such as headaches, discomfort and lower mood.
The Cochrane review is not the first scientific analysis to question the benefits of products touted as blue-light blocking. A 2021 study out of Brigham Young University found that an Apple iPhone feature called “Night Shift” had little effect on sleep, as we reported in “Blue Light Might Not Be So Bad for Your Sleep After All.”