The first doesn’t make sense to me.

The second does but sounds weird.

The third looks okay to me, but beware I’m not a native speaker so perhaps I think it’s grammatically correct but it’s not.

By the way, the sentence feels silly out of context as you present it, and doesn’t make much sense by itself but I’m hoping you have some context that frames it such as another character asking “Who are you looking for?” and a story that explains why you would even be concerned they can see your ears. Maybe it’s an ear-eating monkey that gets triggered when they see ears. Or maybe they can shoot laser beams with their eyes but only aimed at people’s ears. I don’t know. There’s a reason I’m not a writer.