Charles Bonnet syndrome
Pronunciation: SHARL bon-NAY
Condition in which patients with significant visual impairment experience complex, vivid visual hallucinations while maintaining insight into their unreality.
Full Definition
Charles Bonnet syndrome is a neuropsychiatric condition affecting individuals with severe visual impairment who experience complex, formed visual hallucinations. Named after the Swiss philosopher who first described it, the syndrome typically occurs in elderly patients with conditions such as macular degeneration, glaucoma, or diabetic retinopathy. The hallucinations are usually pleasant or neutral, featuring people, animals, or geometric patterns, and patients typically retain insight that these perceptions are not real. The condition is thought to result from visual cortex hyperactivity compensating for reduced visual input.
Usage
Usage note: Named condition - capitalize both words. Distinguish from hallucinations associated with psychiatric disorders or delirium.
In Context
- "The ophthalmologist reassured the patient that her Charles Bonnet syndrome hallucinations were a normal consequence of her vision loss." — Patient consultation note
- "Charles Bonnet syndrome was considered in the differential diagnosis given the patient's intact insight regarding the visual phenomena." — Psychiatric evaluation