eye
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- eye
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The organ of vision; called also oculus. In shape the eyeball (bulbus oculi) is a large sphere, with the segment of a smaller sphere, the cornea, in front.
It is composed of three coats:
-the external tough fibrous tunic or layer, consisting of the white sclera over most of the eyeball and the cornea on the anterior surface;
-the middle vascular tunic or uvea, consisting of the choroid, the ciliary body, and the iris;
-the internal tunic, which is neural and sensory and consists primarily of the retina.
Within the three coats are the refracting media: the aqueous humor, the crystalline lens, and the vitreous humor. The lens is a double convex transparent body between the vitreous and aqueous humors; its convexity is altered by the ciliary muscle during accommodation. Posteriorly, fibers of the optic nerve enter the ganglionic layer and receive sensations from the visual cells of the retina (the retinal rods and retinal cones). The arteries of the eye are the short ciliary, the long ciliary, the anterior ciliary, and the central artery of the retina. The nerves are the optic and the long and short ciliary nerves.
Used in 5 Article abstracts
Used in 5 Article abstracts