The Paris Review has an extended and richly illustrated piece by historian Andrew Scull who tracks how madness has been visually depicted through the ages.
Scull is probably the most thorough and readable historian of madness since the death of the late, great Roy Porter, and this article is no exception.
Modern psychiatry seems determined to rob madness of its meanings, insisting that its depredations can be reduced to biology and nothing but biology. One must doubt it. The social and cultural dimensions of mental disorders, so indispensable a part of the story of madness and civilization over the centuries, are unlikely to melt away, or to prove no more than an epiphenomenal feature of so universal a feature of human existence. Madness indeed has its meanings, elusive and evanescent as our attempts to capture them have been.
By the way, most of the illustrations in the web article seem to be clickable for high resolution full screen versions, so you can see them in full detail.
Link to Madness and Meaning in Paris Review.
Mind Hacks 
I read the following article regarding “Virtual reality and hallucination”. This article does not consider hallucination as an abnormal property and rather accepts it as normal experience:
http://realitysandwich.com/1037/virtual_reality_and_hallucination/
The Medical Encyclopedia offers, Hallucinations are false or distorted sensory experiences that appear to be real perceptions. These sensory impressions are generated by the mind rather than by any external stimuli, and may be seen, heard, felt, and even smelled or tasted. [20] To call an experience a hallucination is an ontological assertion disguised as a psychological term. Every perceptual event with the label hallucination presents a statement about the nature of reality, and a value-position about the perceivers status vis a vis consensus, socially-approved standards of reality or its kissing cousin, truth.
John Lilly gave the following definition of hallucination in an interview with David Jay Brown and Rebecca McClen:
DJB: How would you define what a hallucination is?
“JOHN: Thats a word I never use because its very disconcerting, part of the explanatory principle and hence not useful. Richard Feynman, the physicist, went into the tank here twelve times. He did three hours each time and when he finished he sent me one of his physics books in which he had inscribed, ‘Thanks for the hallucinations.’ So I called him up and I said, ‘Look, Dick, you’re not being a scientist. What you experience you must describe and not throw into the wastebasket called “hallucination.” That’s a psychiatric misnomer; none of that is unreal that you experienced.’ For instance he talks about his nose when he was in the tank. His nose migrated down to his buttonhole, and finally he decided that he didn’t need a buttonhole or a nose so he took off into outer space.
“DJB: And he called that a hallucination because he couldn’t develop a model to explain it?
“JOHN: But you don’t have to explain it, you see. You just describe it. Explanations are worthless in this area.
Though, I disagree with the part that says that explanations are worthless in this area.