astigmatism

a·stig·ma·tism   (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. [a-1 + Greek stigma, stigmat-, point (from stizein, stig-, to tattoo; see steig- in Indo-European roots).] as'tig·mat'ic (ās'tĭg-māt'ĭk) adj. & n., as'tig·mat'i·cal·ly adv.

astigmatism [(uh-stig-muh-tiz-uhm)]

A condition in which the curvature of the cornea of the eye is uneven, causing a blurring of vision. Astigmatism is normally corrected by glasses.

astigmatism 

Main Entry: astig·ma·tism
Pronunciation: &-'stig-m&-"tiz-&m
Function: noun
1 : a defect of an optical system (as a lens)causing rays from a point to fail to meet in a focal point resulting in a blurred and imperfect image
2 : a defect of vision due to astigmatism of the refractive system of the eyeand especially to corneal irregularity —compare EMMETROPIA, MYOPIA

astigmatism a·stig·ma·tism (ə-stĭg'mə-tĭz'əm)
n.
A condition in which unequal curvatures along the different meridians in one or more of the refractive surfaces of the eye cause the rays from a light source not to be focused at a single point on the retina. Also called astigmia.

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as'tig·mat'ic (ās'tĭg-māt'ĭk) adj. & n.

astigmatism   (ə-stĭg'mə-tĭz'əm)  Pronunciation Key  (click for larger image in new window) 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.