Step 1: Try This Simple Sleep Hack, Step 2: Feel Way More Alert During The Day

For the first portion of this study, nearly 100 healthy young people (ages 18 to 35) wore a sleep mask to bed every night for a week. Then, they headed to a lab to have their memory formation, reaction time, and alertness tested. The following week, they did the same thing but without the mask.

Over the course of the two weeks, participants were asked to keep everything else about their sleep routines consistent: Bedtime, wake-up time, etc. They also abstained from drinking coffee and alcohol and taking daytime naps throughout the duration of the study.

Greco's team found that memory formation and alertness scores did indeed improve when participants wore their masks to bed.

To explore the topic further, they designed a second experiment in which a smaller group of 35 adults wore a sleep mask to bed for five nights and then a sleep mask with eye holes cut out for two nights. This was meant to serve as a control mask that gave participants the feeling of sleeping with a mask, without the light-blocking benefits. They also wore EEG headbands to measure sleep stages during this follow-up study.

Again, those with the real mask performed better on post-study cognition tests. After analyzing the EEG data, researchers proposed this could be due to an increase in slow-wave activity in the brain while wearing sleep masks that block light from reaching the retinas.

"Given the current climate of life-hacking, sleep monitoring, and cognitive enhancers, our findings suggest the eye mask as a simple, economical, and noninvasive way to get more out of a night of sleep," the study authors conclude.

This research reiterates the importance of darkness for spurring sleep—and proves that you don't need to head into the woods to get it. Wearing a sleep mask is just one simple, science-backed habit that can have outsized effects on sleep. Here are a few others:

Turn off electronics: Along the same vein as keeping a dark bedroom, turning off electronics at night can help regulate your circadian rhythm and send a signal to your body that it's time to sleep.

Take a magnesium supplement: Magnesium is one ingredient you'll find in sleep-supporting supplements that actually has research behind it. The essential mineral has been shown to help people fall asleep faster1 and stay asleep longer2 in clinical trials. Plus, it's gentle and non-hormonal, making it safe to take nightly and relatively affordable. Here are a few Ph.D.-approved magnesium supplements to look into.