Study questions efficacy of blue-light blocking glasses for eye strain and sleep improvement

Blue-light blocking glasses, widely used to alleviate eye strain and enhance sleep, may not provide the expected benefits, according to a recent comprehensive analysis of 17 studies. 

The analysis found that these Blue-light blocking glasses, designed to shield eyes from the potentially harmful blue light emitted by screens, are unlikely to significantly diminish digital eye strain or improve sleep quality.

The investigation, led by Laura Downie, an associate professor in optometry and vision sciences at The University of Melbourne, examined randomised controlled trials exploring the effects of blue-light glasses on vision, eye health, and sleep quality. It revealed that only a handful of studies demonstrated a marginal reduction in eye strain, and these were conducted over brief periods.

Notably, blue-light filtering lenses generally block only a small portion of blue light, ranging from 10% to 25%, while screens emit relatively limited amounts. Mark Rosenfield, a professor of biological and vision sciences, pointed out that the primary source of blue light exposure is the sun, not screens.

Regarding sleep, the six studies included in the analysis showed mixed results. While some studies indicated positive effects on sleep, these benefits were predominantly observed in specific groups, and there is inadequate evidence to support their general applicability.

The association between blue light and sleep disruption is derived from studies on circadian rhythms, which are more extensively explored in animals than in humans. However, experts suggest that other factors, such as the content viewed on screens and bedtime routines, play a more substantial role in sleep quality.

In light of these findings, experts recommend prioritising other strategies to mitigate eye strain and sleep problems. Maintaining consistent sleep schedules, avoiding caffeine close to bedtime, and refraining from screen usage before sleep are more likely to positively influence sleep quality. 

While Blue-light blocking glasses may not be harmful, they may not provide the anticipated benefits either.