Archive for August, 2012

When our minds play tricks on us (image by Martine Lemmens/stock xchng photo)

This week I am over at Scientific American talking about a topic that just fascinates me, Charles Bonnet Syndrome. This is a condition that I happened to stumble upon while researching something else. I have never seen a patient with it but know of other eye docs who have and the stories that their patients tell are really amazing. One eye doc said that one of their patients had seen pink chickens, another’s had seen babies crawling and their late wife.

Charles Bonnet Syndrome is a condition which affects people who have suffered visual field loss. These people sometimes see images in their vision, images that are sometimes pretty wild and fantastical. In my research I read that some compare Charles Bonnet Syndrome to phantom limb syndrome in that both have neurological sensations that are produced when function is lost but not to worry, the frequency of these phantom sensations (or in the case of Charles Bonnet, haunting imagery) tends to decrease over time.

People with Charles Bonnet syndrome are “psychologically healthy” and their hallucinations involve no other sense (taste, touch, smell, or sound) as in other types of hallucinations. Also, those afflicted are very much aware that what they are seeing is not real though they hasten to tell others about it for fear they might be seen as having cognitive decline or mental impairment which is not the case.

Those with Charles Bonnet should be encouraged to tell others of the unwanted images so that their medical professionals can provide help and reassurance. The hallucinations won’t last forever, once the brain gets used to the newly acquired defects in the visual field the uninvited “visions” will subside.

Oliver Sacks gave a wonderful TED talk on the subject of Charles Bonnet Syndrome in which he quoted Charles Bonnet speaking of visual hallucinations saying that he wondered how “the theater of the mind could be generated by the machinery of the brain.”

How hauntingly complex the visual system is!


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