A study of 17 randomised controlled studies found no evidence that blue light-blocking eyewear improves sleep or reduces computer-related eye strain. The analysis found no indication that blue-light-filtering lenses protect the retina, the light-sensitive tissue at the back of the eye, because the included studies did not look at this result.
Optometrists have been increasingly recommending or prescribing blue-light filtering lenses, also called blue-light-blocking spectacles, since the early 2000s.Together with researchers from City, the University of London, and Monash University, the most recent review was carried out by researchers from the University of Melbourne and published in the Cochrane Database of Systematic Reviews.
The team’s goal was to evaluate the advantages of blue-light-blocking lenses to non-blue-light-blocking eyewear in terms of enhancing visual function, safeguarding the retina, and enhancing sleep quality. They uncovered 17 tests from six different countries after examining the data from every randomised controlled study they could find.
Five to 156 participants took part in a variety of trials, and the lenses were tested for anything from a few hours to five weeks. Associate Professor Laura Downie, Head of the Downie Laboratory: Anterior Eye, Clinical Trials and Research Translation Unit, at the University of Melbourne in Victoria, Australia, is the review’s senior author. She is also a Dame Kate Campbell Fellow.
According to her, employing blue-light-blocking eyewear may not have any immediate advantages to using non-blue-light-blocking eyewear in reducing the effects of computer-related visual tiredness. Additionally, it is presently unknown if these lenses have an impact on sleep-related or vision-related outcomes, and no long-term implications for retinal health could be derived.
When determining whether to buy these glasses, people should consider these findings.However, she added, it’s also important to take into account the research’ quality and length.
“To guarantee that the results are reliable, we carried out the systematic review in accordance with Cochrane methodology criteria. However, the level of the available evidence should be considered when interpreting our level of confidence in the given findings. The brief follow-up time also hindered our capacity to think about potential longer-term effects.
Dr. Sumeer Singh, a postdoctoral research fellow in the Downie Laboratory and the review’s first author, stated that “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. When employing various groups of individuals and lenses, they should look at if efficacy and safety outcomes change.
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, poor mood, and discomfort when wearing the glasses. Similar effects were documented with non-blue-light filtering lenses, therefore these were probably connected to wearing glasses in general.
According to Prof. Downie, there has been a lot of discussion in recent years concerning the use of blue-light-filtering eyeglasses in ophthalmic practise. These lenses are frequently prescribed to patients around the world, according to research, and a variety of marketing claims about their potential advantages exist. For example, they may lessen eye strain brought on by using digital devices, enhance sleep quality, and shield the retina from light-induced damage. Based on the most recent and reliable research, our review’s findings indicate that there is conflicting and ambiguous evidence supporting these statements. Our research does not support the widespread prescription of blue-light-filtering lenses. A wide range of stakeholders, such as eye care specialists, patients, researchers, and the general public, will find these data valuable.
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 generate more blue light than conventional lighting sources and are used for longer periods of time closer to sleep is one justification for claims regarding the advantages of these lenses.
The amount of blue light that our eyes absorb from man-made sources, such as computer displays, is around one thousandth of what they receive from natural sunshine, according to Dr. Singh. It’s also important to keep in mind that, depending on the exact device, blue-light filtering lenses generally block 10–25% of blue light. The lenses would need to have a clear amber hue to effectively filter out greater quantities of blue light, which would have a significant impact on how colours are perceived.