photopsia
   Also known as photome, phosphorescence of the retina, scintillations, and suffusio scintillans. The term photopsia comes from the Greek words photizein (to give light, to illuminate) and opsis (seeing). It is used to denote a group of * simple or * geometric visual hallucinations such as * phosphenes, luminous rays, coruscations, heat waves, * snow lights, and * Moore's lightning streaks. In ordinary parlance, these phenomena are referred to as light flashes. Simple forms of photopsia are designated as * unstructured pho-topsia, while the geometric forms are designated as * structured photopsia. Sometimes photopsia may lead the affected individual to perceive fleeting illusory images or * passage hallucinations. It has been speculated that photopsia may even act as a * point de repère for the development of * complex visual hallucinations. As the British surgeon Walter Cooper Dendy (1794-1871) wrote in 1847, "The brilliant beams in the suffusio scin-tillans, so varied and so whimsical, might be readily moulded into human form by the imagination of an enthusiast or the feelings of the ghost-seer, who is usually morose and melancholy, in a state of longing for a ghost or a mystery." Photopsia may be classified as a subclass of the *positive spontaneous visual phenomenon (PSVP). When attributable to intraocular pathology, it may be classified as an *entoptic phenomenon. Pathophysiologically, photopsia is associated primarily with aberrant neuronal discharges in any part of the visual system. Eti-ologically, it is associated with such diverse conditions as posterior vitreous detachment (PVD), retinal break, acute zonal occult outer retinopathy, retinal migraine, migraine with aura, *migraine aura without headache, metastatic tumours, occipital epilepsy, cocaine intoxication, *hallucinogen-induced persistent perception disorder (HPPD), and *digitalis intoxication. Historically, the term photopsia is used in opposition to the term * morphopsia, the latter term referring in a broad sense to *formed visual hallucinations.
   References
   Amos, J.F. (1999). Differential diagnosis of common etiologies of photopsia. Journal of the American Optometric Association, 70, 485504.
   Dendy, W.C. (1847). The philosophy of mystery. New York, NY: Harper & Brothers.
   Klee, A., Willanger, R. (1966). Disturbances of visual perception in migraine. Acta Neurolog-ica Scandinavica, 42, 400-414.
   Oishi, A., Miyamoto, K., Kashii, S., Yoshimura, N. (2006). Photopsia as a manifestation ofdig-italis toxicity. Canadian Journal of Ophthalmology, 41, 603-604.

Dictionary of Hallucinations. . 2010.

Look at other dictionaries:

  • Photopsia — Pho*top si*a, n. [NL., fr. Gr. fw^s, fwto s, light + ? sight.] (Med.) An affection of the eye, in which the patient perceives luminous rays, flashes, coruscations, etc. See {phosphene}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Photopsia — is the presence of perceived flashes of light. It is most commonly associated with posterior vitreous detachment, migraine with aura, migraine aura without headache, retinal break or detachment, occipital lobe infarction and sensory deprivation… …   Wikipedia

  • photopsia — /fō topˈsi ə/or photopsy / topˈsi/ noun (Gr opsis appearance) the appearance of flashes of light, owing to irritation of the retina • • • Main Entry: ↑photo …   Useful english dictionary

  • photopsia — noun The presence of perceived flashes of light …   Wiktionary

  • photopsia — A subjective sensation of lights, sparks, or colors due to electrical or mechanical stimulation of the ocular system. SEE ALSO: Moore lightning streaks, under streak. SYN: photopsy. [photo + G. opsis, vision] * * * pho·top·sia fō täp sē ə …   Medical dictionary

  • photopsia — n. the sensation of flashes of light caused by mechanical stimulation of the retina of the eye, usually due to traction by the attached vitreous humour when the eye is moved …   The new mediacal dictionary

  • unstructured photopsia —    Also known as phosphene. Both terms are used to denote a type of *photopsia (i.e. a flash of light ) consisting of an unformed shape. The term unstructured photopsia is used in opposition to * structured photopsia. Pathophysiologically, the… …   Dictionary of Hallucinations

  • structured photopsia —    A term used to denote a type of * photopsia (i.e. light flashes) depicting geometric patterns such as circles, squares, hexagonal shapes, etc. The term structured photopsia is used in opposition to *unstructured photopsia and *phosphene. Patho …   Dictionary of Hallucinations

  • Фотопсия (Photopsia) — субъективное ощущение вспышек света, возникающее в результате механического раздражения сетчатки глаза (обычно оно наблюдается при вытяжении стекловидного тела во время движения глаза). Источник: Медицинский словарь …   Медицинские термины

  • фотопсия — (photopsia; фото + греч. opsis зрение) появление в поле зрения мелькающих искр, пятен, зигзагообразных линий и т. п.; возникает при поражениях сетчатки, а также в качестве элементарных зрительных галлюцинаций при некоторых психических… …   Большой медицинский словарь

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”