Micropsia

Micropsia
Illustration from Lewis Carroll's Alice's Adventures in Wonderland depicting the title character seated slouched over in a tiny room. Alice is positioned awkwardly with her weight supported partially by her left forearm, which rests on the floor and spans nearly half of the room's length. Her head is ducked beneath the low ceiling and her right arm reaches outside, resting on an open window's sill. The folds of Alice's dress occupy much of the remaining free space in the room.
The perception a person can have due to symptoms of pronounced micropsia. See § Comparison with Alice's Adventures in Wonderland, below. Image from that same novel.
SpecialtyOphthalmology

Micropsia is a condition affecting human visual perception in which objects are perceived to be smaller than they actually are. Micropsia can be caused by optical factors (such as wearing glasses), by distortion of images in the eye (such as optically, via swelling of the cornea or from changes in the shape of the retina such as from retinal edema, macular degeneration, or central serous retinopathy), by changes in the brain (such as from traumatic brain injury, epilepsy, migraines, prescription drugs, and illicit drugs), and from psychological factors. Dissociative phenomena are linked with micropsia, which may be the result of brain-lateralization disturbance.[1]

Micropsia is also commonly reported when the eyes are fixating at (convergence), or focusing at (accommodation), a distance closer than that of the object[2] in accord with Emmert's law. Specific types of micropsia include hemimicropsia, a form of micropsia that is localized to one half of the visual field and can be caused by brain lesions in one of the cerebral hemispheres.

Related visual distortion conditions include macropsia, a less common condition with the reverse effect, and Alice in Wonderland syndrome, a condition that has symptoms that can include both micropsia and macropsia.

  1. ^ Lipsanen T, Korkeila J, Saarijärvi S, Lauerma H (March 2003). "Micropsia and dissociative disorders". Journal of Neuro-Ophthalmology. 23 (1): 106–7. doi:10.1097/00041327-200303000-00060. PMID 12616098.
  2. ^ Pinker S (1997). How the mind works. New York: W. W. Norton & Company. ISBN 9780393045352.