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 你 look into someone's eyes 你 can see into the soul, so he hides eyes so no one can see into him. -Cake