- excessive constriction of the pupil of the eye, as a result of drugs, disease, or the like.
Origin of miosis
1810–20; variant of myosis < Greek mý(ein) to shut (the eyes) + -ōsis -osis
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for myosis
An example of this kind of myosis is the action of muscarine.Poisons: Their Effects and Detection
Alexander Wynter Blyth
Myosis produced by means of solutions of various drugs, a myosis followed by reduction of intra-ocular tension.Glaucoma
Examination showed slight atrophy of both optic nerves, Argyll-Robertson pupil, and myosis.Fat and Blood
S. Weir Mitchell
- a variant spelling of miosis
- excessive contraction of the pupil of the eye, as in response to drugs
- a variant spelling of meiosis (def. 1)
C20: from Greek muein to shut the eyes + -osis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for myosis
Online Etymology Dictionary, © 2010 Douglas Harper
- Variant ofmiosis
- The period of decline of a disease in which the intensity of the symptoms begins to diminish.
- Constriction of the pupil of the eye, resulting from a normal response to an increase in light or caused by certain drugs or pathological conditions.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.