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astigmatism

Syllabification: a·stig·ma·tism
Pronunciation: /əˈstiɡməˌtizəm
 
/

Definition of astigmatism in English:

noun

A defect in the eye or in a lens caused by a deviation from spherical curvature, which results in distorted images, as light rays are prevented from meeting at a common focus.
Example sentences
  • Whether myopia, hyperopia or astigmatism is present, surgical correction attempts to redirect light rays to accommodate the refractive error.
  • Side vision is distorted and oblique rays of light passing through a spherical lens produce astigmatism.
  • Apart from testing the eye, they supply booklets detailing eye care with particular reference to refractive errors such as myopia, hypermetropia and astigmatism.

Origin

mid 19th century: from a-1 'without' + Greek stigma 'point' + -ism.

Derivatives

astigmatic

1
Pronunciation: /ˌastiɡˈmatik/
adjective
Example sentences
  • The astigmatic person does not know which focal line to look at, and hunting between the two may cause eyestrain.
  • Monet, on seeing those fields, described them as ‘enough to drive a poor painter crazy - impossible to render with our poor colors,’ but render them he did in his astigmatic but beautiful way.
  • Ordinary soft lenses tend to mould to the astigmatic curve, but special toric soft lenses are available for astigmatism.

Definition of astigmatism in:

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