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contact lens
contact lens Lens worn on the cornea to aid defective vision. Invented in 1887, lenses were initially made of glass. Modern contact lenses, developed (1948) by Kevin Tuohy, are made of plastic. Hard (corneal) lenses cover the pupil and part of the cornea. They are usually gas-permeable (allowing oxygen to reach the cornea). Soft (hydrophilic) lenses cover the whole cornea and are hydrated in saline solution.
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"contact lens." World Encyclopedia. 2005. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. "contact lens." World Encyclopedia. 2005. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O142-contactlens.html "contact lens." World Encyclopedia. 2005. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O142-contactlens.html |
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contact lens
con·tact lens • n. a thin plastic lens placed directly on the surface of the eye to correct visual defects. |
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Cite this article
"contact lens." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 9 Feb. 2012 <http://www.encyclopedia.com>. "contact lens." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 9, 2012). http://www.encyclopedia.com/doc/1O999-contactlens.html "contact lens." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 09, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-contactlens.html |
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