In the year 1760, a Swiss naturalist named Charles Bonnet became concerned when his grandfather Charles Lullin began to experience a parade of "amusing and magical visions." The eighty-nine-year-old Lullin was being visited by visions of people, birds, carriages, and buildings, all of which were invisible to everyone but him. Apparently these mysterious objects materialized spontaneously among the few bits of the world he was still able to perceive through his cataracts.
Bonnet's grandfather did not demonstrate any other signs of marble loss, in fact he seemed quite sane aside from the vivid hallucinations. Moreover, the elderly man was keenly aware that the strange sights were all in his mind. Bonnet cataloged his grandfather's curious circumstances, and over time the condition he described came to be known as Charles Bonnet Syndrome, or CBS. Numerous similar cases have been recorded in the decades since, and though it has long been regarded as a rare disease, recent evidence suggests that it is much more widespread than previously believed.
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