Charles Bonnet Syndrome affects 10-50% of patients with significant visual loss, who suddenly develop vivid, complex recurrent visual hallucinations, often “lilliputian” hallucinations (where characters or objects are smaller than normal), of faces, people, artoons, animals, or even trees and inanimate objects.
The syndrome is named after Swiss naturalist Charles Bonnet, who in 1769 described this phenomenon in his 89-year-old grandfather, nearly blind from cataracts in both eyes, but claiming to see men, women, birds, carriages, buildings, tapestries, physically impossible circumstances and scaffolding patterns
It is felt by some to be a visual release phenomenon – images generated by regions of the brain deprived of normal sensory input.
There is no known effective treatment, but symptoms usually resolves within a year or 18 months, and most patients are simply reassured to hear it is a normal phenomenon.
Watch a televised lecture by Dr Oliver Sacks entitled “What hallucination reveals about our minds”:
Click here for a link to a review of Dr Sacks’ book “Hallucinations”.
Click here to link an NPR story on Charles Bonnet syndrome entitled “Blind Man ‘Sees'”.