Afterimage

An afterimage is an image that continues to appear in the eyes after a period of exposure to the original image. An afterimage may be a normal phenomenon (physiological afterimage) or may be pathological (palinopsia). Illusory palinopsia may be a pathological exaggeration of physiological afterimages. Afterimages occur because photochemical activity in the retina continues even when the eyes are no longer experiencing the original stimulus.^[1]^[2]

The remainder of this article refers to physiological afterimages. A common physiological afterimage is the dim area that seems to float before one's eyes after briefly looking into a light source, such as a camera flash. Palinopsia is a common symptom of visual snow.

^ Bender, MB; Feldman, M; Sobin, AJ (Jun 1968). "Palinopsia". Brain: A Journal of Neurology. 91 (2): 321–38. doi:10.1093/brain/91.2.321. PMID 5721933.
^ Gersztenkorn, D; Lee, AG (Jul 2, 2014). "Palinopsia revamped: A systematic review of the literature". Survey of Ophthalmology. 60 (1): 1–35. doi:10.1016/j.survophthal.2014.06.003. PMID 25113609.

[1] Bender, MB; Feldman, M; Sobin, AJ (Jun 1968). "Palinopsia". Brain: A Journal of Neurology. 91 (2): 321–38. doi:10.1093/brain/91.2.321. PMID 5721933.

[2] Gersztenkorn, D; Lee, AG (Jul 2, 2014). "Palinopsia revamped: A systematic review of the literature". Survey of Ophthalmology. 60 (1): 1–35. doi:10.1016/j.survophthal.2014.06.003. PMID 25113609.

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