i used to go in school suspension alot in high school, and met someone that figured out how sleep with his eyes open, it looked kinda strange really.
some of the profs at my school would let the student sleep through the period now, if you were a rook (a recruit for the corps of cadets) and an upperclassman caught you sleeping in class, you got your ass chewed out after class - well, thats how it was when i was a rook, its changed a bit now