They’re cheaper than blackout curtains. Researchers who study sleep are pretty unanimous in the assessment that the darker your room, the better your sleep. But most of us don’t live in caves, and so the only way to make your bedroom totally dark is with blackout curtains—a costly proposition if you’ve got big windows. As an alternative, you can simulate darkness by using a sleep mask to keep ambient light (or, if you’re a day-sleeper, daylight) from hitting your eyes
They improve your sleep quality. The primary reason that those scientists say you need darkness for good sleep is actually evolutionary. Humans—and our pre-human ancestors—are naturally diurnal, meaning we’re awake during the day and sleep at night. For thousands of years before electric lights allowed us to keep working or socializing late into the evening, humans naturally slept while it was dark and were awake during the day. Our brains are hard-wired into associating darkness with sleep, and they produce more melatonin (the hormone that controls our sleep and wake cycles) when they sense an absence of light.
They might help your insomnia. Because our brains associate darkness with sleep, it may be possible to utilize a sleep mask in muting the “noise” (stress, anxiety, excitement, etc.) in our brains that’s keeping us up at night. Sleep masks also make it impossible for you to open your eyes and look at the temptations and distractions around your room or at your alarm clock, which sleep scientists say should be out of sight from your sleeping position anyway.
They’re safer than medication or alcohol. A lot of people who have trouble sleeping use sleeping pills or self-medicate with alcohol in order to get some rest. But pharmaceutical sleeping aids—even non-prescription ones—can be habit-forming or come with side effects. (Plus, the chance of overdose is real.) And alcohol not only comes with the same risks as sleeping pills, but it also disrupts your sleep cycle and has a negative impact on the overall quality of your rest.
Because sleep masks trick your brain into believing it’s time for sleep, they’re a low-risk, non-chemical alternative to more conventional sleep aids, but you may find they’re just as effective.