Charles Bonnet hallucinations: a case series.

Charles Bonnet hallucinations are complex visual hallucinations which occur during clear consciousness in patients who do not suffer from psychosis, substance abuse, sleep disorders, focal neurological lesions or acute eye disease. They are well-defined images of patterns, scenes, animals or humans combined with normal perceptions and elicit a neutral or pleasant emotional response. Because of conflicting reports about cognitive or visual impairments among patients with these hallucinations, I describe the cognitive and visual status of 13 patients. One patient had preserved cognition and vision; three had preserved cognition and impaired vision; three had impaired cognition and preserved vision; and six had both impaired cognition and vision. It is unlikely that cognitive or visual deficits alone caused the hallucinations, but may have contributed to a state of sensory deprivation with visual phenomena.