OP, I have a serious answer! Might stay buried, but whatever. I worked at a certain type of hospital (Don't want to be too specific) and got to hang out with a completely blind patient for 12 hours straight.

He was a really cool dude, an old hippie. He lost one eye to a congenital defect and then later on lost the other to a blunt trauma. Sensing that he was "chill" over the course of our conversations about music and such, I asked him if he used to smoke weed, and subsequently psychedelics. He said he ate mushrooms and acid frequently before he lost his sight, and still eats it occasionally since he lost it. I asked him what the trips are like now.

He described it as mainly being an auditory and mind fuck kind of trip. "Visually" he said he could feel the usual hallucinations, but not actually see them. I interpreted it as perhaps feeling like you're looking at a fractal, and sensing the movement of it in your mind, but not registering it visually.