The review pooled three randomized crossover trials that compared blue-blocking glasses with clear lenses and reported actigraphy outcomes.

Across studies, pooled differences were small and not significant: about 9 minutes longer total sleep time, about 5 minutes shorter sleep onset latency, about 1.5 minutes less wake after sleep onset, and about 0.6 percentage points lower sleep efficiency. Actigraphy is a wrist-movement method used to estimate sleep timing.

Twenty healthy adults completed a two-week randomized crossover trial wearing blue-blocking or clear glasses for three hours before bedtime.

Subjective sleep onset and awakenings improved slightly, but actigraphy, a wrist-movement sleep tracker, showed no objective sleep improvement and total sleep time averaged about 433 minutes with blue-blocking versus about 449 minutes with clear lenses.

Twenty patients with major depressive disorder and sleep-onset insomnia were randomized to blue-blocking or clear lenses for two weeks, worn from 8 PM to bedtime.

Changes in sleep-quality ratings did not differ between groups, indicating that blocking blue light did not materially improve sleep quality in this clinical group.

Forty-three bipolar outpatients with insomnia wore blue-blocking or placebo glasses for two weeks from evening to bedtime.

Self-reported sleep quality and actigraphy sleep measures showed no significant differences between groups, indicating no clear sleep benefit from blocking blue light in this sample.

Sixty healthy pregnant women were randomized to wear full blue-blocking or partially blue-blocking glasses for two weeks, following a one-week baseline.

Sleep diaries and actigraphy, a wrist-movement sleep tracker, showed no significant differences in total sleep time, sleep efficiency, or sleep midpoint between groups, suggesting little practical sleep impact from added blue blocking.

Researchers surveyed smartphone users about blue-light filter app use and sleep quality.

Most users did not use filter apps, and the analysis found no sustained positive effects on overall sleep quality, with a limited association only in the 31-40 age group.

Twenty-four healthy adults completed lab nights under 3000 K OLED, 3000 K LED, and dim-light conditions with polysomnography, a full overnight sleep lab recording.

Melatonin onset was delayed under OLED and LED versus dim light, but sleep latency, total sleep time, and sleep efficiency were largely similar, with only modest differences in deep sleep under LED.

Nine healthy men completed two conditions: evening exposure to blue LED light and a no-light control, followed by polysomnography, a full overnight sleep lab recording.

Sleep architecture and sleep efficiency were similar between the two conditions, indicating minimal impact on objective sleep structure despite other physiological effects.

The meta-analysis pooled eight studies comparing blue-filtering and standard intraocular lenses after cataract surgery, totaling 1,007 patients.

Subjective sleep quality improved slightly in the short term, but the difference was small and no clear long-term advantage was found, suggesting limited practical sleep impact from blue filtering.