Old People See Things

November 22, 2011

Brit Trogen

Old age brings all sorts of ailments for us to look forward to. Macular degeneration and glaucoma will take our eyes, our ears will fall prey to presbycusis, our bones will creak with arthritis. But one thing you may not have known to watch out for is hallucinations. Anywhere from 10-40% of the visually- and hearing-impaired populations are believed to experience full-fledged hallucinations, ranging from visual images of cartoons and people, to weird sounds and music. In the case of visual hallucinations, one very odd syndrome is to blame...


Someone just spotted a unicorn...


Charles Bonnet syndrome is a special condition that only afflicts people with decreased vision abilities or blindness.The hallucinations are like bizarre, silent movies, playing out before the eyes of the watcher, who is unable to stop them. They can be anything —animals, cartoons, people in strange costume, shapes, even yourself— and they come and go very suddenly, with little to no warning.


If you didn't realize that grandma might be tripping out while she's watching Lawrence Welk, that's because only a tiny portion (about 1%) of the people afflicted with these hallucinations actually report them, out of fear of being misdiagnosed as plain old crazy. But there's a very simple test to determine whether or not your hallucinations are the harmless Charles Bonnet kind or truly psychotic: the crazy ones talk. Psychotic illusions almost always address whoever is experiencing them directly, which is how the "voices" in someone's head can occassionally cause problems. 


So what's the cause of these strange but harmless visions? Studies making use of fMRI's have shed light on the problem, showing that as you lose vision, there are no longer stimuli feeding into the visual parts of the brain. To compensate, these optic pathways begin firing spontaneously. Unfortunately, there's no effective treatment of this syndrome, though letting the person know that they're really not crazy is often enough to prevent undue anxiety.


But often, after a couple years of the decreased vision the brain will adjust and the visions might recede on their own. So, when that fateful day comes, just remember: this, too, shall pass. Hopefully.



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