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A large proportion of those with CBS develop the visual hallucinations as vision begins to deteriorate and stop hallucinating once vision is entirely gone. [10] Complex hallucinations may progress over time if the primary loss of vision is due to damage of the early cortical areas. [10]
The content of hallucinations varies as well. Preliminary research has found that most individuals had multiple types of visual hallucinations. [20] Scenes involving people and/or animals were the most common, followed by simple geometric images. [4] Complex (formed) visual hallucinations are more common than Simple (non-formed) visual ...
About 30% of patients report visual hallucinations of the removed eye. [1] Most of these hallucinations consist of basic perceptions (shapes, colors). In contrast, visual hallucinations caused by severe visual loss without removal of the eye itself (Charles Bonnet syndrome) are less frequent (prevalence 10%) and often consist of detailed images.
Palinopsia (Greek: palin for "again" and opsia for "seeing") is the persistent recurrence of a visual image after the stimulus has been removed. [1] Palinopsia is not a diagnosis; it is a diverse group of pathological visual symptoms with a wide variety of causes. Visual perseveration is synonymous with palinopsia. [dubious – discuss]
It most commonly occurs in people over the age of fifty and in the United States is the most common cause of vision loss in this age group. [ 1 ] [ 3 ] About 0.4% of people between 50 and 60 have the disease, while it occurs in 0.7% of people 60 to 70, 2.3% of those 70 to 80, and nearly 12% of people over 80 years old.
The palinoptic images are not typically reliant on environmental parameters and often present with homonymous visual field deficits. Hallucinatory palinopsia occurs unpredictably and the persistent images can appear anywhere in the visual field, regardless of the location of the original stimulus. A patient will often have only a few episodes ...
Illusory palinopsia is often worse with high stimulus intensity and contrast ratio in a dark adapted state.Multiple types of illusory palinopsia often co-exist in a patient and occur with other diffuse, persistent illusory symptoms such as halos around objects, dysmetropsia (micropsia, macropsia, pelopsia, or teleopsia), Alice in Wonderland Syndrome, visual snow, and oscillopsia.
Hallucinogen persisting perception disorder (HPPD) is a non-psychotic disorder in which a person experiences apparent lasting or persistent visual hallucinations or perceptual distortions after using drugs, [1] including but not limited to psychedelics, dissociatives, entactogens, tetrahydrocannabinol (THC), and SSRIs.