A blind man hallucinating

NPR has an brief but interesting piece on a blind man who has visual hallucinations.

Stewart, the person in question, lost his sight due to hereditary sight-loss, but has developed Charles Bonnet syndrome, a curious condition where playful visual hallucinations are common.

Two things about this condition are striking: firstly, the hallucinations are typically complex and intricate but the damage is typically only to the retina, the cortex remains intact.

Secondly, unlike many other conditions where hallucinations are common, the person typically retains complete insight. They know they are hallucinating and typically don’t mistake hallucinations for the real world.

While the person interviewed in this radio segment is blind, Charles Bonnet syndrome can occur in people with partial sight, who may have only lost vision in one part of their visual field (often due to macular degeneration). In these cases, even when the hallucinations can ‘blend in’ with true vision, the person usually knows the difference.

One of the most remarkable things about the interview is that the Stewart’s hallucinations can be triggered by quite idiosyncratic things (such as foods and thoughts) and that he takes such joy in the experience.

If you want to read more about the syndrome, the Fortean Times published a great article on it back in 2004.

Link to NPR segment on Charles Bonnet syndrome.
Link to FT article on the same.

One Comment

  1. airship1951
    Posted February 4, 2008 at 2:52 pm | Permalink

    I used to have cataracts. They were congenital – I was born with them. They got worse as I got older. Eventually I was unable to drive, and about a decade ago they decided to remove my lenses and replace them with plastic ones. What a wonderful difference!
    But here is how my experience relates to this particular post: Before my surgery, when the light was right my mind would often interpret a thing as something else. For example, I often saw a pair of black socks sitting on the floor as a rat. Not a scary rat, but a black rat, with eyes and whiskers, the whole ‘rat’ thing going on. Now, I knew there wasn’t a rat – in fact, I was always sure it was a pair of black socks, because the two were always related. So I relaxed and enjoyed it – in fact, I often laughed in genuine surprise and joy when I saw it. It was just one of those interesting little surprises that my condition threw at me to make life interesting.
    I saw other illusions, too, but none was as consistent in its presentation as the ‘sock rat’.


Post a Comment

Required fields are marked *
*
*

Follow

Get every new post delivered to your Inbox.

Join 22,875 other followers