Robyn Rutgers ’24
Computer usage is integral to daily life; however, prolonged electronic usage is associated with vision-related problems, or “computer vision syndrome.” Symptoms include blurred vision, dry eyes, redness, and headaches. Some have hypothesized that computer vision syndrome is a result of exposure to blue light emitted from computer screens, causing businesses to market blue-light-blocking lenses as a potential solution. However, a lack of evidence makes it difficult to assess the efficacy of these lenses. Thus, researchers at the University of Melbourne conducted a study to investigate the efficacy of blue-light-blocking lenses in reducing symptoms of eye strain resulting from computer use.
A total of 120 symptomatic computer users participated in a randomized control trial testing the efficacy of blue-light-blocking lenses. Researchers assigned participants into positive and negative advocacy groups, then further sub-randomized participants to receive either clear placebo lenses or blue-light-blocking lenses. Prior to intervention, researchers showed participants in the positive advocacy group a video presenting the intervention in a positive light, and those in the negative advocacy group a video presenting the intervention in a negative light. Participants then performed a two-hour computer task involving data spreadsheet entry and checks with their respective lenses. Participants self-reported symptoms before and after the intervention as a subjective measure of eye strain. Additionally, participants’ critical flicker-fusion frequency, the threshold frequency of flickering at which a person can distinguish between flickering and steady light, was measured before and after the intervention as an objective measure of eye strain.
Contrary to expectations, researchers found no significant difference in critical flicker-fusion frequency or symptom survey scores between blue-light-blocking and control spectacle lenses groups. Furthermore, results showed advocacy type had no effect on either score. Thus, researchers concluded that blue-light-blocking lenses do not alleviate symptoms of eye strain associated with computer use.
The hypothesis that blue light emitted from computer screens causes computer vision syndrome has led to the marketing of lenses reducing blue light transmission, despite a lack of evidence. As a consumer, it is important to be aware of evidence supporting the efficacy of products. The results of this study suggest that blue-light-blocking lenses do not reduce computer-induced eye strain; however, it is important to note that the two-hour computer task may have been insufficient in producing eye strain. Future research may investigate the long-term usage of such glasses for the prevention of eye strain.
 S. Singh, L. Downie, and A. Anderson, Do blue-blocking lenses reduce eye strain from extended screen time? A double-masked randomized controlled trial. American Journal of Ophthalmology 226, 243-251 (2021). doi: /10.1016/j.ajo.2021.02.010
 Image retrieved from: https://pixabay.com/nl/photos/bril-licht-tafel-reflectie-2593033/