The continued use of screens –smartphone, computer, tablet, television…– has contributed to the emergence of potential measures to protect eye health and minimize associated discomfort, and among these, blue light filters for glasses stand out. It is quite common that if we need to correct vision in optics, they recommend this type of lens to which the ability to reduce visual fatigue or protect the retina, among other advantages, is attributed.
However, there is no scientific evidence to support these qualities, and a review of studies just published in the Cochrane Database of Systematic Reviews has concluded that “the results of the review do not support the prescription of spectacles with blue light filter to the general population”.
The study was carried out by researchers from the University of Melbourne (Australia), who reviewed the scientific literature to find papers that compared the use of blue light filter lenses with normal glasses with the aim of improving visual performance, protect the retina and improve sleep quality. Although the screens of digital devices do emit some degree of blue light, claims that blue light-filtering glasses reduce digital eye strain have been questioned.
“The use of blue light filter glasses to reduce eye strain associated with computer use may not have short-term advantages compared to glasses without a blue light filter”
In fact, in recent years experts have questioned the use of fear of the harmful effects of blue light as a commercial strategy to sell these products, and in 2017 the Spanish Society of Ophthalmology already warned that the use of blue light could not be recommended. blue light blockers because “current scientific evidence does not show that blue light damages the eye and the benefit of blue filters in preventing eye damage from such light radiation.”
The researchers selected a total of 17 randomized controlled trials that had been conducted between 2009 and 2021 in six countries with data from 619 patients (the number of participants ranged from 5 to 156), and in which the effects of of the use of this type of lens for a variable period: from less than one day to a maximum of five weeks. The ‘short term’ period for evaluating the interventions ranged from two hours to one week of use.
Implications for eye health professionals and consumers
Following systematic review of the trials, the researchers found that “the use of blue light filter glasses to reduce eye strain associated with computer use may have no short-term advantage compared with glasses without a blue light filter.” blue. It is also not currently clear whether these glasses affect the quality of vision or sleep, and no conclusions can be drawn about the possible long-term effects on retinal health. People should take these findings into account when deciding whether to buy these glasses,” said Laura Downie, lead author of the review and Associate Professor of Optometry and Vision Science at the University of Melbourne.
Downie said these lenses are often prescribed to patients and there are many marketing claims about their potential benefits that patients may find confusing. “The results of our review, based on the best current available evidence, show that the evidence is inconclusive and uncertain for these claims,” he notes.
“Our findings do not support the prescription of blue light filtering lenses for the general population. These results are relevant to a wide range of stakeholders, including eye health professionals, patients, researchers, and the community at large.”
Dr Sumeer Singh of the University of Melbourne, a postdoctoral researcher at the Downie Laboratory and first author of the review, explained that the amount of blue light our eyes receive from artificial sources, such as computer screens, is about one thousandth. part of which we receive from natural light.
“Large, high-quality clinical research studies with longer follow-up in more diverse populations are still required to more clearly determine the potential effects of blue-light filtering spectacle lenses on visual performance, sleep, and health. eye,” he says.
“They should examine whether the efficacy and safety results vary between different groups of people and the use of different types of lenses,” said this expert, adding that “it is also worth bearing in mind that light-filtering lenses Blue light filters typically filter 10-25% of blue light, depending on the specific product. Filtering out higher levels of blue light would require the lenses to have a noticeable amber tint, which would have a substantial effect on color perception.”
