|
|
1. (n.) astigmatism
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. astigmatism
an aberration of a lens or other optical system in which the image of a point is spread out along the axis.
Etymology: (1840–50)
|
| Definition of 'astigmatism' |
Princeton's WordNet |
|
1. (noun) astigmatism, astigmia
(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people
2. (noun) astigmatism, astigmia
(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point
|
| Definition of 'astigmatism' |
Webster Dictionary |
|
1. (noun) astigmatism
a defect of the eye or of a lens, in consequence of which the rays derived from one point are not brought to a single focal point, thus causing imperfect images or indistinctness of vision
|
| Definition of 'astigmatism' |
U.S. National Library of Medicine |
|
1. astigmatism
Unequal curvature of the refractive surfaces of the eye. Thus a point source of light cannot be brought to a point focus on the retina but is spread over a more or less diffuse area. This results from the radius of curvature in one plane being longer or shorter than the radius at right angles to it. (Dorland, 27th ed)
|
|
|
|
|
| Alternative search options for 'astigmatism' |
|
|
|
|
|
|
|
Definitions of astigmatism 
