Wearing an Eye Mask During Sleep Proves Beneficial for Next-Day Alertness

Wearing an eye mask during sleep can improve next-day alertness, according to a study published in the journal Sleep.

The quality and quantity of sleep affects brain function, which has important implications for cognitive functioning. Some studies have found that wearing an eye mask during sleep has positive effects on subjective sleep outcomes.

To more objectively evaluate the effect of wearing an eye mask during sleep, healthy volunteers with no problems falling asleep were recruited at the Cardiff University Brain Research Centre in the United Kingdom.

Participants (n=94) in experiment 1 wore an eye mask for 5 consecutive nights (days 1-5) following their usual sleeping schedule and arrived in the mornings on days 6 and 7 at the center to undergo cognitive testing. The following week the same procedure was followed with a control eye mask. In experiment 2, participants (n=35) followed a similar procedure, but the participants switched between the eye mask and control mask every other night. The participants wore an electroencephalogram device during sleep, they measured light intensity in their bedroom as soon as they woke up, and cognitive testing occurred on days 4 and 5.

In experiment 1, after wearing the eye mask, participants had faster reaction times (mean, 310.26 vs 316.37; P =.006) and improved word-pair association scores (mean, 65.06 vs 63.87; P =.023) compared with scores after wearing the control mask, respectively.

In experiment 2, the post-eye mask score for word-pair encoding was higher (mean, 69.9) than the post-control mask score (mean, 67.7; P =.049). Learning performance correlated with (SWS) time after a night of sleeping with the eye mask (r, 0.51; P =.011) but not with the control mask (r, 0.00; P =.99).

The eye mask did not affect the number of hours slept (P =.914), self-reported sleep quality (P =.131), or comfort (P =1.000).

This study was limited by the loss of some participants due to lack of compliance.

The researchers concluded that the use of an eye mask during sleep can lead to better memory performance and higher alertness the following day.

“Given the current climate of life-hacking, sleep monitoring, and cognitive enhancers, our findings suggest the eye mask as a simple, economical, and non-invasive way to get more out of a night of sleep,” they concluded.