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[kawr-nee-uh] /ˈkɔr ni ə/
noun, Anatomy
the transparent anterior part of the external coat of the eye covering the iris and the pupil and continuous with the sclera.
1350-1400; Middle English < Medieval Latin cornea (tēla, later tunica) horny (web or tunic), feminine of corneus corneous
Related forms
corneal, adjective
multicorneal, adjective
precorneal, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for pre corneal


noun (pl) -neas (-nɪəz), -neae (-nɪˌiː)
the convex transparent membrane that forms the anterior covering of the eyeball and is continuous with the sclera
Derived Forms
corneal, adjective
Word Origin
C14: from Medieval Latin cornea tēla horny web, from Latin cornūhorn
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
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Word Origin and History for pre corneal



late 14c., from Medieval Latin cornea tela "horny web or sheath," from Latin cornu (genitive cornus) "horn" (see horn (n.)). So called for its consistency. Related: Corneal.

Online Etymology Dictionary, © 2010 Douglas Harper
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pre corneal in Medicine

cornea cor·ne·a (kôr'nē-ə)
The transparent, convex, anterior portion of the outer fibrous coat of the eyeball that covers the iris and the pupil and is continuous with the sclera.

cor'ne·al adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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pre corneal in Science
The tough transparent membrane of the outer layer of the eyeball that covers the iris and the pupil.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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pre corneal in Culture
cornea [(kawr-nee-uh)]

The transparent outer covering of the front of the eye that covers the iris and pupil.

The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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Encyclopedia Article for pre corneal


dome-shaped transparent membrane about 12 mm (0.5 inch) in diameter that covers the front part of the eye. Except at its margins, the cornea contains no blood vessels, but it does contain many nerves and is very sensitive to pain or touch. It is nourished and provided with oxygen anteriorly by tears and is bathed posteriorly by aqueous humour. It protects the pupil, the iris, and the inside of the eye from penetration by foreign bodies and is the first and most powerful element in the eye's focusing system. As light passes through the cornea, it is partially refracted before reaching the lens. The curvature of the cornea, which is spherical in infancy but changes with age, gives it its focusing power; when the curve becomes irregular, it causes a focusing defect called astigmatism, in which images appear elongated or distorted.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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