A group of psychologists and sleep experts from Cardiff University in the United Kingdom found that wearing a sleep mask improves cognitive function the next day. The results of the research were published in the journal To sleep.
The study involved 89 volunteers. During the week, participants spent 5 nights wearing eye masks and then participated in a 2-day trial. During the second week, the experiment was repeated, but without mask.
The researchers found that participants performed better in learning on the word-pair association task after sleeping with the mask. They also performed better on the psychomotor alertness test, which measures behavioral alertness and sustained attention. Taken together, this suggests that the mask helped improve participants’ cognitive abilities.
Interestingly, the participants’ sleep diaries showed no difference in sleep hours or sleep quality scores between the two weeks.
The second experiment involved 33 people. This time, participants slept with an eye mask for two nights and a similar mask for two nights, but with cuts. Meanwhile, the scientists collected EEG data from the volunteers’ brains.
“Higher learning efficiency after wearing the mask was associated with a longer duration of non-REM sleep, which is enhanced by the inability of the eyes to capture light,” the scientists said.