If you cross your eyes for a long period of time, it would definitely hurt. But would they stay that way forever?

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"Don't cross your eyes -- they'll stick that way!" That's something most of us have heard from our mothers at one time or another. Can they actually stick? Let's take a look at how your eyes work.

Your eyeballs are controlled by six muscles. When you look up, down, left or right, the muscles attached to your eyeballs make this movement happen. When you cross your eyes, you're simply telling your muscles to move your eyes inward together. This is something you naturally do when you look at something that's very close to your face.

So was mom's warning just a ruse so you would stop tormenting your younger brother with another one of your gross-out maneuvers? The answer to that question is yes. Although crossing your eyes for an extended period of time might cause a temporary strain on your eye muscles, no medical evidence suggests that they would stick that way. You would most likely suffer from some eye spasms or twitches, and your eyes might feel a bit fatigued, but they would certainly return to normal within an hour or so.