If you cross your eyes, they will get stuck like that.
A childhood belief about eyes

others believed things like this
- if you cross your eyes and there's a gush of wind, you'll get stuck like that !!— Olivier
- I used to think that all people closed their eyes and stuck their tongue out when they died.Anon
- I used to think that "cross-eyed" meant that people had X's for eyes, like dead people in cartoons.— Tim
- when I saw a sign with a deer on it I always thought deer had to cross the street by it. like a cross walk— only me
- I was born brunette with brown eyes and dark hair, i thought people with blue eyes, had water in them.Anon
- When I was little my friend told me that if you snease with your eyes open you eyes will fall out!Anon