macropsia

[mah-krop´se-ah]

an illusion in which objects appear larger than their actual size.

ma·crop·si·a

(mă-krop'sē-ă),

Perception of objects as larger than they are.

[macro- + G. opsis, vision]

Farlex Partner Medical Dictionary © Farlex 2012

macropsia

A disorder of visual perception (dysmetropsia) in which objects in the visual field appear larger than normal, some forms of which have been fancifully termed the “Alice in Wonderland” syndrome. Retinal macropsia is attributed to compression of receptor spacing, resulting in greater stimulation and a larger perceived image.

Aetiology
Aniseikonia, prescription drugs (e.g., citalopram, zolpidem), illicit drugs (e.g., LSD, psilocybin, marijuana), migraines, epilepsy, hypolycaemia, EBV virus infection, prions.

macropsia

Abnormal perception of the size of objects so that they seem larger than they actually are.

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

macropsia

Anomaly of visual perception in which objects appear larger than they actually are. It may occur as a result of abnormal accommodation (less than required for the fixation distance) or because of various retinal anomalies in which the visual receptors are crowded together, or because of the recent wear of either base-in prisms or a presbyopic correction, etc. Syn. megalopsia. See dysmegalopsia; micropsia; meta-morphopsia.

Mentioned in

References in periodicals archive

Zolpidem-induced macropsia in anorexic woman (letter).

Zolpidem may cause visual distortions and other psychotic symptoms

The authors found that certain phenomena--such as increased intensity of colors, increased vividness of objects, macropsia, micropsia, and transient paranoia--were specific to the cocaine-induced psychotic state.

Cocaine-induced psychosis and schizophrenia

The early symptoms of macular disease include metamorphopsia (distortion of vision), micropsia, macropsia, and delayed recovery after exposure to bright lights (so that the headlights of oncoming cars may make night driving very difficult).

Loss of vision in the ageing eye

The clinical manifestation of an ERM can be completely asymptomatic or profoundly symptomatic with metamorphopsia, micropsia or macropsia, decreased visual acuity (VA), and loss of central vision.

Comparison of Visual Outcome and Morphologic Change between Different Surgical Techniques in Idiopathic Epiretinal Membrane Surgery

Common visual disturbances attributed to HPPD are recurrent geometric hallucinations, perception of peripheral movement, colored flashes, intensified colors, palinopsia, positive afterimages, haloes around objects, macropsia, and micropsia occurring spontaneously in individuals with no prior psychopathology.

Hallucinogen sequelae