Do Blue-Blocking Lenses Reduce Eye Strain Due to Extended Screen Time? A Double-Mask Randomized Controlled Trial

PMID: 33587901 DOI: 10.1016/j.ajo.2021.02.010

Commentary

The purpose of this study was to investigate whether blue-blocking lenses are effective in reducing ocular signs and symptoms of eye strain associated with computer use.

A total of 120 computer users were randomly (1:1) assigned to the "positive" and "negative" advocacy arms.

Participants were further sub-randomized (1:1) to receive clear (placebo) or blue-blocking glasses.

All participants were led to believe they had received a positive intervention and performed a 2-hour computer task while wearing their assigned eyeglass intervention.

The pre-specified primary outcome measures were eye strain symptom scores and the mean change in critical flicker fusion frequency (CFF, an objective measure of eye strain) (minus the post-computer task).

As a result, no significant effects were identified for CFF in the primary analysis for advocacy type (positive or negative, p = .164) and eyeglass intervention type (blue blocking or clear lenses, p = .304). Similarly, there was no difference in eye strain symptom scores for advocacy (p = .410) or eyeglass lens type (p = .394).

Adverse events were not documented.