Disease & Epidemiology
Palinopsia refers to a pathological group of visual symptoms in which there is an abnormal persistence or recurrence of an image in time. Palinopsia derives its name from the Greek word palin which means "again" and opsia which means "seeing.”
Palinopsia is distinct from a physiological after-image, which is a benign, normal response in which an image briefly persists after a person has stopped looking at the original visual stimulus. Images from palinopsia are longer-lasting and more intense than physiological after-images. Whereas physiological after-images appear immediately after removal of the original visual stimulus, palinopsia after-images may appear immediately or after a time interval. Images from palinopsia are positive images, or the same colors as the original visual stimulus, whereas physiological after-images are negative images, or complementary colors of the original visual stimulus [1].
Palinopsia can be categorized into two general categories: hallucinatory palinopsia and illusory palinopsia [2]. Individuals with hallucinatory palinopsia see images that are long-lasting, high-resolution, and occur anywhere within the visual field. Individuals with illusory palinopsia see images that are affected by immediate environmental factors, such as light and motion. The images from illusory palinopsia are short-lasting, low-resolution and indistinct.
There is limited data on the epidemiology of palinopsia. Palinopsia may occur in up to 10% of migraineurs and seem to occur more frequently in migraine with aura than without aura [3]. Although migraines occur more frequently in females than males and more frequently in younger to middle aged populations than elderly populations [4], there have not been significant studies done comparing palinopsia between the categories.
