The point of a sleep mask is to help block out light and help you fall asleep faster and stay asleep.
Sleeping in the dark is the best way to sleep.
When there's no light coming into your eyes it helps tell your body adjust and tell your brain it's time to sleep.
Since I started wearing a sleep mask I found that I started sleeping better and falling asleep much faster as well.
If you're having trouble falling asleep or you have light coming into your room when trying to sleep then using a sleep mask is a good way to help you go to sleep.
Also sleep masks help people sleep in the day as well when they need to work at night.
I used to work at night and had trouble sleeping during the day and when using the sleep mask it helped me sleep much better.