Visual hallucinations can be frightening, or pleasant. Unformed visual hallucinations consist of seeing distorted or mis-formed lights, lines, objects, or shapes. Visual hallucinations, with the exception of religious experiences, are abnormal. Visual hallucinations can result from changes in the brain, temporary or permanent, caused by electrolyte disturbances, high fevers, liver or kidney failure or drugs. Parkinson patients with dementia, and Parkinson patients suffering from an intellectual decline without dementia, are more likely to experience hallucinations on anti-Parkinson drugs.
Visual hallucinations are abnormal.
They must be reported. Illusions Visual illusions differ from visual hallucinations. Visual illusions are distortions, misperceptions, or false impressions of real objects. Visual illusions can consist of seeing an animal's form or shape in a cloud. Or seeing a person's form or shape in a chair or a coat-rack.