astigmatism

[ uh-stig-muh-tiz-uhm ]

noun

1. Also called a·stig·mi·a [uh, -, stig, -mee-, uh]. 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.
2. 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.

astigmatism

/ əˈstɪɡmɪə; əˈstɪɡməˌtɪzəm /

noun

1. a defect of a lens resulting in the formation of distorted images; caused by the curvature of the lens being different in different planes
2. faulty vision resulting from defective curvature of the cornea or lens of the eye

astigmatism

/ ə-stĭg′mə-tĭz′əm /

1. 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.

astigmatism

1. 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.

Word History and Origins

Origin of astigmatism¹

First recorded in 1840–50; astigmat(ic) + -ism

Example Sentences

Lo and behold, Hernández learned his right eye had astigmatism, a condition caused by imperfections in the curvature of the eye that can result in blurred vision.

From Los Angeles Times

The reason: A recent diagnosis of astigmatism in his right eye.

From Los Angeles Times

Schanuel struggled in 2022 with the Harbor Hawks while unknowingly playing with an astigmatism in his right eye.

From Los Angeles Times

This past winter, Schanuel went to an eye doctor and learned he had astigmatism in his right eye, which was increasingly affecting his ability to see the ball.

From Los Angeles Times

Patrick writes of emerging from a depressive cycle as an experience akin to getting sober: “When you can suddenly see things clearly after years of blur and astigmatism, you may love some details and other details may set your teeth on edge.”

From Los Angeles Times