Do Blue-blocking Lenses Reduce Eye Strain From Extended Screen Time? A Double-Masked Randomized Controlled Trial

PURPOSE: To investigate if blue-blocking lenses are effective in reducing the ocular signs and symptoms of eye strain associated with computer use. DESIGN: Double-masked, randomized controlled trial. METHODS: A total of 120 symptomatic computer users were randomly assigned (1:1) into a positive or negative advocacy arm (ie, a clinician either advocating or not advocating for the intervention via a prerecorded video). Participants were further sub-randomized (1:1) to receive either clear (placebo) or blue-blocking spectacles. All participants were led to believe they had received an active intervention. Participants performed a 2-hour computer task while wearing their assigned spectacle intervention. The prespecified primary outcome measures were the mean change (post-minus pre-computer task) in eye strain symptom score and critical flicker-fusion frequency (CFF, an objective measure of eye strain). The study also investigated whether clinician advocacy of the intervention (in a positive or negative light) modulated clinical outcomes. RESULTS: All participants completed the study. In the primary analysis, for CFF, no significant effect was found for advocacy type (positive or negative, p = .164) and spectacle intervention type (blue-blocking or clear lens, p = .304). Likewise, for eye strain symptom score, no differences were found for advocacy ( p = .410) or spectacle lens types (p = .394). No adverse events were documented. CONCLUSIONS: Blue-blocking lenses did not alter signs or symptoms of eye strain with computer use relative to standard clear lenses. Clinician advocacy type had no bearing on clinical outcomes. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

This study aimed to investigate if blue-blocking lenses are effective in reducing eye strain associated with computer use, and the results showed that blue-blocking lenses did not alter signs or symptoms of eye strain. Additionally, clinician advocacy type did not have any impact on clinical outcomes.