astigmatism
Also called a·stig·mi·a [uh-stig-mee-uh]. /əˈstɪg mi ə/. Ophthalmology. a refractive error of the eye in which parallel rays of light from an external source do not converge on a single focal point on the retina.
Optics. an aberration of a lens or other optical system in which the image of a point is spread out along the axis of the system.
Origin of astigmatism
1Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024
British Dictionary definitions for astigmatism
astigmia (əˈstɪɡmɪə)
/ (əˈstɪɡməˌtɪzəm) /
a defect of a lens resulting in the formation of distorted images; caused by the curvature of the lens being different in different planes
faulty vision resulting from defective curvature of the cornea or lens of the eye
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
Scientific definitions for astigmatism
[ ə-stĭg′mə-tĭz′əm ]
A visual defect in which the unequal curvature of one or more refractive surfaces of the eye, usually the cornea, prevents light rays from focusing clearly at a single point on the retina, resulting in blurred vision.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Cultural definitions for astigmatism
[ (uh-stig-muh-tiz-uhm) ]
The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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