Mad-Eye Moody's eye...?

Well, imagine having his magical eye. Does it automatically see through everything? That would be seriously creepy...he can see through people's clothes, right..? Ew :L
atau does it just see through things when Mad-Eye wants to see through that specific object..? That seems weird because for example when he sees Dobby's knitted socks Harry is wearing, why would he be choosing to look at harry's socks? It seems like he notices things while scanning a room atau whatever...In which case, he could eaily be a complete pervert!

What do anda think? An I completely mad..? :L