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Definition of Astigmatism
1. Noun. (ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea; common in nearsighted people.
Category relationships: Ophthalmology
Generic synonyms: Ametropia
Specialized synonyms: Keratectasia, Keratoconus
Derivative terms: Astigmatic, Astigmatic
2. Noun. (optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point.
Category relationships: Optics
Generic synonyms: Condition, Status
Derivative terms: Astigmatic, Astigmatic
Antonyms: Stigmatism
Definition of Astigmatism
1. n. 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
1. Noun. (optics) A defect of a lens such that light rays coming from a point do not meet at a focal point so that the image is blurred. ¹
2. Noun. (pathology) A disorder of the vision, usually due to a misshapen cornea, such that light does not focus correctly on the retina causing a blurred image. ¹
¹ Source: wiktionary.com
Definition of Astigmatism
1. [n -S]
Medical Definition of Astigmatism
1.
Lexicographical Neighbors of Astigmatism
Literary usage of Astigmatism
Below you will find example usage of this term as found in modern and/or classical literature:
1. Text-book of Ophthalmology by Ernst Fuchs (1911)
"If the» is no astigmatism worth mentioning, the patient sees worse through the
cylindrical ... J The astigmatism is frequently found to be greater* after ..."
2. The American Journal of the Medical Sciences by Southern Society for Clinical Investigation (U.S.) (1887)
"But this latter type is extremely rare, corneal asymmetry constituting, almost
without exception, the total astigmatism; when the crystalline is affected, ..."
3. Refraction and how to refract by James Thorington (1910)
"Optically, astigmatism may be defined as the refractive condition in which rays of
... In ophthalmology astigmatism is recognized as that condition of the ..."
4. Manual of the diseases of the eye: For Students and General Practitioners by Charles Henry May (1901)
"astigmatism (As.) is that refractive condition of the eye in which there is a
... In astigmatism, since the refractive surfaces are not spherical, ..."
5. The Medical Times and Gazette (1885)
"By the term " astigmatism " we understand a condition of asymmetry of the ...
The first form is known as regular, the second as irregular astigmatism. ..."
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