macropsia
   Also known as macropsy, macroptic vision, megalopsia, and megalopia. The term macropsia comes from the Greek words makros (large) and opsis (seeing). It refers to a visual distortion in which objects and stimuli are perceived as disproportionally large. The process ofincreas-ing the apparent size of objects and stimuli is called "magnification. When macropsia sets in gradually rather than abruptly, it is called " zoom vision. When objects are repeatedly magnified and minified in the course of seconds, the term " pulsation phenomenon applies. Macropsia is classified either as a type of "dysmetropsia or as a " metamorphopsia. It can occur physiologically in the form of " oculomotor macropsia, but it can also occur in the context of neurological disease. In the context of disease, macropsia may present as an isolated symptom, as part of an "aura, or as part of a cluster of symptoms called the " Alice in Wonderland syndrome. Etiologically, macropsia is associated primarily with paroxysmal neurological disorders such as epilepsy and migraine. It can also be evoked by intoxication with alcohol or with "hallucinogens such as LSD and mescaline. In " hemimacropsia, the perceived enlargement of objects restricts themselves to one of the visual hemifields. The term "central macropsia is used to denote a type of macrop-sia that restricts itself to the central field of vision, leaving objects and stimuli perceived in the periphery of the visual field in their normal proportions. The term macropsia is used in opposition to " micropsia. It should not be confused with the term " macroptic hallucination. Conceptually, macropsia can be considered the visual equivalent of "macrostereognosia (i.e. feeling things as larger than they are). The two conditions have also been known to occur in conjunction.
   References
   Critchley, M. (1949). Metamorphopsia of central origin. Transactions ofthe Ophthalmologic Society of the UK, 69, 111-121.
   Park, M.-G., Choi, K.-D., Kim, J.S., Park, K.-P., Kim, D.-S., Kim, H.-J., Jung, S. (2007). Hemi-macropsia after medial temporo-occipital infarction. Journal ofNeurology, Neurosurgery and Psychiatry, 78, 546-548.

Dictionary of Hallucinations. . 2010.

Look at other dictionaries:

  • Macropsia — is a neurological condition affecting human visual perception, in which objects appear larger than normal, and the subject smaller. It is the reverse of micropsia.Causes of macropsia include migraines and (rarely) complex partial epilepsy.… …   Wikipedia

  • macropsia — f. oftalm. Alteración de la visión en la que los objetos se ven más grandes de lo que son en realidad. Se opone a micropsia. Medical Dictionary. 2011. macropsia …   Diccionario médico

  • macropsia — /makro psia/ s.f. [comp. di macr(o ) e opsia ]. (med.) [disturbo della visione per il quale gli oggetti appaiono più grandi del reale] ▶◀ megalopsia. ◀▶ micropsia …   Enciclopedia Italiana

  • macropsia — s. f. Visão que avoluma os corpos.   ‣ Etimologia: macro + opsia …   Dicionário da Língua Portuguesa

  • Macropsia — La macropsia es un desorden neurológico que afecta la percepción visual, haciendo que los objetos sean percibidos más grandes de lo que son en realidad; siendo este síndrome inverso a la micropsia. Un claro ejemplo se ve en Alicia en el País de… …   Wikipedia Español

  • macropsia — Eng. Macropsia Visión de los objetos de un tamaño mayor al real. Macropía. Megalopsia. Megalopía …   Diccionario de oftalmología

  • Macropsia — La macropsia es un desorden neurológico que afecta a la percepción del ojo humano, haciendo que los objetos sean percibidos más grandes de lo que son en realidad; siendo este síndrome el inverso a la micropsia …   Enciclopedia Universal

  • macropsia — /meuh krop see euh/, n. Ophthalm. a defect of vision in which objects appear to be larger than their actual size. Also, macropia /meuh kroh pee euh/, macropsy /mak rop see/. Also called megalopsia, megalopia. Cf. micropsia. [1885 90; < NL; see… …   Universalium

  • macropsia — noun A disorder in which objects appear much larger than normal, most often the result of a neurological dysfunction. Syn: macropsy Ant: micropsia …   Wiktionary

  • macropsia — Perception of objects as larger than they are. [macro + G. opsis, vision] * * * mac·rop·sia ma kräp sē ə also mac·rop·sy ma .kräp sē n, pl sias also sies a condition of the eye in which objects appear to be unnaturally large compare MICROPSIA * * …   Medical dictionary

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