astigmatism
[ uh-stig-muh-tiz-uh m ]
/ əˈstɪg məˌtɪz əm /
noun
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
First recorded in 1840–50;
astigmat(ic) +
-ism
Words nearby astigmatism
asthmatic,
asti,
asti spumante,
astigmatic,
astigmatic lens,
astigmatism,
astigmatizer,
astigmatometer,
astigmatoscope,
astigmatoscopy,
astigmia
Example sentences from the Web for astigmatism
British Dictionary definitions for astigmatism
astigmatism
astigmia (əˈstɪɡmɪə)
/ (əˈstɪɡməˌtɪzəm) /
noun
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
Medical definitions for astigmatism
astigmatism
[ ə-stĭg′mə-tĭz′əm ]
n.
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 one point on the retina, resulting in blurred vision.
astigmia
Other words from astigmatism
as′tig•mat′ic (ăs′tĭg-măt′ĭk) adj. n.Scientific definitions for astigmatism
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.