I was shooting my semi auto .22 pistol today at the range and got hit on the bottom eyelid of my right eye with a spark or whatever you'd call it and I'm not gonna lie. It hurt, not to mention it scared the crap out of me. I'm just thankful it was there and not in my eye.
We wear them when we shoot for the very same reason. We've been hit too many times when shooting our pistols. We have several pairs and make the kids wear them as well when they shoot.