"I see things flat. Whenever there is a sudden change I see it flat. That's why I'm reluctant to go forward. It's as if there were a wall there and I would walk into it. There's no depth, but if I take time to look at things I can pick out the pieces like a jigsaw puzzle, then I know what the wall is made of. Moving is like a motion picture. If you move, the picture in front of you changes. The rate of change in the picture depends on the speed of walking. If you run you receive the signals at a faster rate. The picture I see is literally made up of hundreds of pieces. Until I see into things I don't know what distance they are away."
This is a hallucination that Oliver Sacks calls "mosaic vision" in his wonderful book, Migraine; in fact the cover of the book is a painting of mosaic vision. I think I had this happen to me once when I woke in the middle of the night, probably going back to sleep quickly, so I almost forgot. Even when I read Sacks's description I didn't remember right away. In my memory, I am experiencing this hallucination as I am trying to get to the sink, and it was very hard to find my way, as you might imagine. I have been hoping for it to happen again so I can have a clearer memory of the experience, but probably I won't get my wish.