swinging flashlight test


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Marcus Gunn pupil

A change in the pupillary reflex, caused by unilateral optic nerve or retinal disease.

Method
A light is shone, first on one eye and then the other, with the opposite eye covered; the affected eye demonstrates a slight contraction or dilation of the pupil.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

swinging flashlight test

Neurology A test for comparing direct and consensual reactions of each pupil, to ID afferent pupillary defects. See Marcus Gunn pupil.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

swinging flashlight test

A test used to detect a relative afferent pupillary defect or Marcus Gunn pupil. Direct light is shone into the normal eye; both pupils constrict equally due to the consensual response. Light is quickly swung over to the contralateral pupil, which appears to dilate as a result of a relative decrease in the optic nerve fiber function in the affected eye. This response is seen in asymmetrical optic nerve diseases such as glaucoma, optic neuropathy, and optic neuritis.
Medical Dictionary, © 2009 Farlex and Partners