According to an analysis of 17 randomized controlled studies, the strongest known research to date, blue light-blocking eyewear likely has no effect on computer-related eye strain or sleep quality.
The included studies did not analyze this outcome, hence the analysis did not uncover any proof that blue-light-filtering lenses shield against harm to the retina, the light-sensitive tissue at the back of the eye. Blue-light filtering lenses, also known as blue-light blocking spectacles, have been increasingly prescribed or recommended, often by optometrists, since the early 2000s.
Researchers at the University of Melbourne in collaboration with colleagues at City, University of London and Monash University led the new review, published in the Cochrane Database of Systematic Reviews.
The team’s goal was to evaluate the benefits of blue-light-blocking lenses to non-blue-light-blocking glasses for enhancing visual performance, shielding the retina, and enhancing sleep quality. They searched for randomized controlled trials on the subject and discovered 17 trials from six different nations after analyzing the data from all of them.
Participant counts in various experiments ranged from five to 156, and the length of time used to evaluate the lenses was somewhere between a few hours to five weeks.
The senior author of the review is Associate Professor Laura Downie, Dame Kate Campbell Fellow and Head of the Downie Laboratory: Anterior Eye, Clinical Trials and Research Translation Unit, at the University of Melbourne, Victoria, Australia.
The outcomes of our review, based on the current, best available evidence, show that the evidence is inconclusive and uncertain for these claims. Our findings do not support the prescription of blue-light filtering lenses to the general population. These results are relevant to a broad range of stakeholders, including eye care professionals, patients, researchers and the broader community.
Professor Laura Downie
She said, “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. People should be aware of these findings when deciding whether to purchase these spectacles.”
However, the quality and duration of the studies also needs to be considered, she said.
“We performed the systematic review to Cochrane methodological standards to ensure the findings are robust. However, our certainty in the reported findings should be interpreted in the context of the quality of the available evidence. The short follow-up period also affected our ability to consider potential longer-term outcomes.”
The first author of the review, Dr. Sumeer Singh, a postdoctoral research fellow in the Downie Laboratory, said, “High-quality, large clinical research studies with longer follow-up in more diverse populations are still required to ascertain more clearly the potential effects of blue-light filtering spectacle lenses on visual performance, sleep and eye health. They should examine whether efficacy and safety outcomes vary between different groups of people and using different types of lenses.”
Inconsistent reports of negative side effects from using blue-light-filtering lenses were not discovered during the review. Any effects tended to be minor, sporadic, and transient. They included headaches, low mood, and discomfort while wearing the glasses. Similar effects were documented with non-blue-light filtering lenses, so these were probably connected to wearing glasses in general.
Prof. Downie said, “Over the past few years, there has been substantial debate about whether blue-light filtering spectacle lenses have merit in ophthalmic practice. Research has shown that these lenses are frequently prescribed to patients in many parts of the world, and a range of marketing claims exist about their potential benefits, including that they may reduce eye strain associated with digital device use, improve sleep quality and protect the retina from light-induced damage.”
“The outcomes of our review, based on the current, best available evidence, show that the evidence is inconclusive and uncertain for these claims. Our findings do not support the prescription of blue-light filtering lenses to the general population. These results are relevant to a broad range of stakeholders, including eye care professionals, patients, researchers and the broader community.”
It’s unknown how blue-light-filtering lenses could be able to reduce eye strain, improve sleep quality, or safeguard the retina. The fact that modern digital gadgets like computers and smartphones emit more blue light than conventional lighting sources and are used for longer periods of time closer to bedtime is one justification for claims regarding the advantages of these lenses.
Dr. Singh said, “The amount of blue light our eyes receive from artificial sources, such as computer screens, is about a thousandth of what we get from natural daylight. 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 color perception.”
