I think they're one of his ways of dealing with stuff, similar to an addiction... they shield his eyes and provide a barrier between him and the real world, so to speak. Also, he might think they look cool. But I think they're mainly a protection.
I think he wears goggles to shield himself from the real world and the cruel things it does. He likes to pretend he is in his own orange-tinted world. A world worthy enough to be a video game. He also thinks it makes him looks cool and badass. (Which it does) He believes in that sappy crap about when bạn look into someone's eyes bạn can see into the soul, so he hides eyes so no one can see into him. -Cake