Some people have lost their eyesight, but they continue to “see.” This phenomenon, a kind of vivid visual hallucination, is named after the Swiss doctor, Charles Bonnet, who described in 1769 how his completely blind grandfather experienced vivid, detailed visions of people, animals and objects. Charles Bonnet syndrome, which appears in those who have lost their eyesight, was investigated in a study led by scientists at the Weizmann Institute of Science. The findings, published today in Brain, suggest a mechanism by which normal, spontaneous activity in the visual centers of the brain can trigger visual hallucinations in the blind.
