Blue-blocking lenses do little for digital eye strain

Blue-blocking lenses fall short of reducing the ocular signs and symptoms of eye strain associated with computer use, according to a study.

A total of 120 symptomatic computer users participated in the study. They were randomly assigned to a “positive” or a “negative” advocacy arm, where a clinician did or did not advocate for the use of blue-blocking lenses via a prerecorded video, respectively. The participants were further randomized to receive either clear (placebo) or blue-blocking spectacles, with all of them led to believe they had received the latter.

To assess the effect of the intervention, the participants performed a 2-hour computer task while wearing their assigned spectacles. The primary outcome measures were the change in eye strain symptom score and critical flicker-fusion frequency (CFF; an objective measure of eye strain). Clinician advocacy of the intervention (in a positive or negative light) was also assessed whether it modulated clinical outcomes.

All participants completed the study. Results revealed no significant changes in both outcomes. CFF did not differ by advocacy type (positive or negative, p=0.164) and by spectacle intervention type (blue-blocking or clear lens, p=0.304). The same was true for eye strain symptom score, which was similar across the advocacy (p=0.410) and spectacle lens type (p=0.394) groups.

There were no adverse events recorded.