An Eye Mask Enhances Deep Sleep and Improves Memory and Alertness

Sleep and body temperature are directly influenced by the daily cycles of sunlight and darkness and their effect on melatonin, a naturally occurring hormone found in the brain. When the sun rises, melatonin concentrations decrease. This promotes wakefulness and increased alertness by signaling body temperature to rise. When the sun sets, melatonin levels rise, prompting our body temperature to decline. As body temperature drops at night, alertness wanes and we fall asleep. Accordingly, ambient bedroom light at night can affect sleep through light’s effect on melatonin and body temperature.

A study in the journal Sleep explored weather wearing an eye mask to block light during overnight sleep impacts sleep, memory, and alertness. Ninety-four 18–35-year-olds wore an eye mask while they slept every night for a week, then underwent a control condition in which light was not blocked for another week. They also wore a device to monitor sleep. The results revealed superior memory and alertness when wearing an eye mask, and this improvement was due to more time spent in deep sleep. These findings suggest that wearing an eye mask during overnight sleep can increase deep sleep and improve memory and alertness the next day.