Visual hallucinations in the elderly.

Visual hallucinations, without auditory hallucinations and in the elderly, are not usually based on previous psychiatric illness. The elderly can, of course, hallucinate as part of severe depression or a life-long schizophrenia, but the clinician should assume that there is an organic basis when an elderly individual begins to develop visual hallucinations for the first time. Representative cases that illustrate visual hallucinations due to ophthalmological, vascular, or degenerative processes are presented. Visual hallucinations can be linked to disorders in multiple parts of the nervous system. Even when related to medications, dementia may also be contributory, as is illustrated by the hallucinations seen in those with Parkinson's disease. Treatment of visual hallucinations is treatment of the underlying cause although some newer drugs such as clozapine may also be helpful for selected patients.