1) Ametropia 2) Astigmia 3) Eye defect 4) Eyesight defect
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https://www.crosswordclues.com/clue/astigmatism
1) Astigmia 2) Keratectasia 3) Keratoconus
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https://www.crosswordclues.com/clue/astigmatism
A condition of the eye where the principal meridians have different refractive errors, requiring a toric lens to fully correct the vision. (Often caused when the corneal surface is not spherical, being more like the surface of a barrel or a rugby ball).
Found on
http://eyediologyopticians.co.uk/pages/Eye-terms-explained.html
• (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.
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http://thinkexist.com/dictionary/meaning/astigmatism/
(from the article `aberration`) Astigmatism, unlike spherical aberration and coma, results from the failure of a single zone of a lens to focus the image of an off-axis point at a ... If only the 3 term is present, then[4 related articles]
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http://www.britannica.com/eb/a-z/a/116
A lens or mirror defect in which the size and shape of an image vary for different points of focus. Light passing through different parts of an astigmatic lens, for example, is focused at different distances beyond the lens, so that the image of a point can appear variously as a short horizontal or ...
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http://www.daviddarling.info/encyclopedia/A/astigmatism.html
a focus defect in which electrons, in different axial planes, focus at different axial distances
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http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=531-42-16
An optical defect where an image is focused into a cross or ellipse and is caused by optics that are not a uniform, spherical shape.
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http://www.encyclo.co.uk/local/20448
<ophthalmology> A visual disturbance caused by an error in the refraction of light within the eye. ... (27 Sep 1997) ...
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http://www.encyclo.co.uk/local/20973
(ә-stig´mә-tiz-әm) an error of refraction in which a ray of light is not sharply focused on the retina, but is spread over a more or less diffuse area; it is due to differences in curvature in the refractive surfaces (cornea and lens) of the eye. adj., astigmat´ic., adj. ...
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http://www.encyclo.co.uk/local/21001
A condition in which the surface of the cornea is not spherical, but bulges more in one axis than the other, like the back of a spoon. An astigmatic cornea causes light images to focus on two separate points in the eye, creating a distorted image and poor focus. Contact lenses designed to correct for astigmatism are called Toric-lenses.
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http://www.encyclo.co.uk/local/21361
A·stig'ma·tism noun [ Greek
'a priv. + ..., ..., a prick of a pointed instrument, a spot, from ... to prick: confer French
astigmatisme .]
(Med. & Opt.) 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 p...
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http://www.encyclo.co.uk/webster/A/136
(uh-STIG-muh-tiz-um) Optical defect in which refractive power is not uniform in all directions (meridians) Light rays entering the eye are bent unequally by different meridians, which prevents formation of a sharp image focus on the retina Slight uncorrected astigmatism may not cause symptoms, but a large amount may result in significant blurrin
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http://www.eyeglossary.net/
Our Astigmatism Main Article provides a comprehensive look at the who, what, when and how of Astigmatism Astigmatism: A common form of visual impairment in which part of an image is blurred, due to an irregularity in the curvature of the front surface of the eye, the cornea. The curve of the cornea is shaped more like an American football or a rugb...
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http://www.medterms.com/script/main/art.asp?articlekey=2374
(ua-stig;mua-tiz;em) Unequal curvature of the refractive surfaces of the eye (cornea and/or lens), so that light entering the eye along certain meridians does not focus on the retina.
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http://www.mhhe.com/biosci/abio/glossary.mhtml
Astigmatism is a malformation or imperfection, congenital or accidental, of the globe of the eye, in consequence of which the individual does not see objects clear and distinct, but with a blurred outline. It is due to the cornea or transparent outer coat of the eye not being regularly spherical, but having different degrees of curvature in differe...
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http://www.probertencyclopaedia.com/browse/EA.HTM
A lens aberration or defect that is caused by the inability of a single lens to focus oblique rays uniformly. Astigmatism causes an object point to appear as a linear or oval-shaped image.
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http://www.rodsmith.org.uk/photographic%20glossary/rods%20photographic%20gl
a focusing distortion which is present at all distances, it can be cancelled out by a cylindrical component in an ophthalmic prescription (marked CYL on prescriptions). The angle of slant of the distortion is called its axis.
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http://www.trayner.co.uk/Info/Glossary.html
a condition of the eye in which the cornea curves severely, like a football, instead of having a normal rounded shape. Astigmatism is inherited, and can occur in combination with nearsightedness or farsightedness
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https://sciencetrek.org/sciencetrek/topics/eyes/glossary.cfm
An aberration, or defect, in a mirror or lens that causes the image of a point to spread out into a line. See also: Aberration.
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https://www.encyclo.co.uk/local/20687
a disorder in which the front surface of the eye (the cornea) is not correctly spherical, resulting in blurry vision
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https://www.encyclo.co.uk/local/20875
Aberration occurring in the lens of the eye. It results when the curvature of the lens differs in two perpendicular planes, so that rays in one plane may be in focus while rays in the other are not. With astigmatic eyesight, the vertical and horizontal cannot be in focus at the same time; correction is by the use of a lens that reduces the over...
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https://www.encyclo.co.uk/local/21221
Also calleda 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. · 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.
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https://www.infoplease.com/dictionary/astigmatism
a vision problem that is due to an abnormal curvature of the eye. It can result in blurred images.
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https://www.stanfordchildrens.org/en/topic/default?id=glossary---growth-and
a vision problem that results in blurred images.
Found on
https://www.stanfordchildrens.org/en/topic/default?id=pediatric-glossary---
No exact match found.
