I'm trying to come up with riddles for a Support chain in my game, but can't really think of many original ones. So I got the idea to make a thread where we come up with and share riddles.  If you're interested in contributing a riddle and I like it, you'll get a contributor's credit in my game.  Of course, you can always just share riddles for fun (which is why I put this in Forum Games). So I'll start: "What helps you see, but blinds you when you look at it?"