Well it probably means he like you but it could also mean something was on you
Well,there are a few reasons for that,either he likes you,he thinks your pretty, or he likes to mentally rape girls (not to be nasty or anything,but some guys minds work that way). He could like you,he could like your looks,or maybe you make his day everytime he sees you.
Run for the hills!!! Hes trying to play mind games on you!
I assuming he thinks you are pretty. And he just can't look away.