The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
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Radial keratotomy (RK) is a surgical procedure in which precisely placed micro incisions are made in a patient's cornea--the clear matter which covers the eyeball--to permanently correct near-sightedness, or myopia. In myopia, the curvature of the cornea causes light rays entering the eye to fall short of the retina. Radial keratotomy flattens the eyeball minutely, allowing light rays to focus at the retina. First performed in Japan in 1955 by T. Sato, Soviet ophthalmologist Svyatoslav Fyodorov developed the procedure in the 1970s after removing glass splinters from a patient whose vision actually improved once the eye healed. The procedure was brought to the United States in 1977 and further refined. Although once considered a risky procedure--and there are still risks involved--more than one million people worldwide have undergone treatment. In most instances, RK can improve myopic vision to 20/40 or better, even though some cases the patient still needs lenses due to under-correction and in others because of over-correction which causes far- sightedness.
Other permanent procedures as alternatives to RK include photorefractive keratectomy (PRK) which uses an excimer (ultraviolet) laser to vaporize corneal tissue; automated lamellar keratectomy (ALK), in which a microkeratome is used to remove portion of the cornea which is frozen, reshaped by grinding, and sewn back into the eye; laser-assisted intrastromal keratomileus (LASIK), which combines portions of ALK and LASIK to make a tiny flap on the cornea through which the inside layers are reshaped and the flap then closed; and orthokeratology--flattening the cornea by the rubbing of hard contact lenses which exert pressure on the eye.