Dr. House journeys to the center of his mind.
This episode was pretty good, although in general I'm not a fan of "It was all a dream" storytelling.
I think the fact that House asked for the ketamine at the end was an indication of personal growth. He's willing to rid himself of the disability that he, on some level, likes having because it gives him a great excuse to be miserable and cranky. I doubt the writers would allow House to be permanently cured, but I think they could do great things with a storyline wherein the pain goes away but gradually seeps back.
I really didn't need to see that eyeball popping out of its socket. I really didn't.