CBS is very common amongst people with vision loss, although until about 20 years ago it was thought to be rare, presumably because of underreporting.
Sacks is a gifted author and neurologist, who writes about patients with great compassion and empathy. In his book he describes many case histories of patients who see hallucinations of great vividness.
I described some of the hallucinations I have experienced in an earlier posting ‘Such stuff as dreams are made on’. In the days that followed the hallucinations I see have gradually evolved. One form, mentioned by Sacks, is the text hallucination. I’ve seen tables of mathematical symbols, and even snatches of equations, and I can even make out a few of the characters but when I try to read further they blur and slip away from me. Sacks describes patients who see musical notation a11 who saw Hebrew letters.
I’ve tried to give an impression of my text hallucinations in the sketches below.
I’ve also seen faces and parts of faces, including my own but sort of rubberised, as though I were a cartoon character; hands; something like a leprechaun; and something like a gorilla. And rather fascinatingly I saw a cat. It’s real cat and his name is Ted. I worked on a photograph of Ted to try and give an idea of what I saw looking out of my computer screen.
None of these objects seem conscious of me in any way. They just flit by silently and are gone in a second or two. They sometimes startle me by popping up suddenly, but it doesn’t seem as if they have any intent.
The most unnerving illusion is that I can see is a shadow on my right hand side, just out of the corner of my eye. It’s a shadow of me. It’s a doppelgänger.
I know it’s not a real shadow because it’s always in the same place, irrespective of where the light is coming from, and if I turn to look at the shadow it vanishes.
Yesterday upon the stair
I met a man who wasn’t there
He wasn’t there again today
Oh, how I wish he’d go away
— Hughes Mearns