Perfect for blocking the light so you can sleep!
I have never tried a sleep mask before and was hesitant because I do tend to sleep on my side the most and other side-sleeping reviewers indicated it didn't work well for side sleeping.  I bought it because I don't sleep well when there is any type of light in a room.  When I finally needed it to sleep during the day, it worked better than expected.  It was uncomfortable for the first couple of seconds and then, I slept for several hours and woke refreshed.  Wish I would have purchased years ago!  I had no problems with side-sleeping so maybe it just depends on the type of pillow you use.
Rating: 5 stars