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Nearsightedness - Overview

Alternative Names

Myopia; Shortsightedness; Refractive error - nearsightedness

Definition of Nearsightedness:

Nearsightedness is when light entering the eye is focused incorrectly, making distant objects appear blurred. Nearsightedness is a type of refractive error of the eye.

If you are nearsighted, you have trouble seeing things that are far away.

Causes, incidence, and risk factors:

People are able to see because the front part of the eye bends (refracts) light and points it to the back surface of the eye, called the retina.

Nearsightedness occurs when the physical length of the eye is greater than the optical length.

This makes it more difficult for the eyes to focus light directly on the retina. If the light rays are not clearly focused on the retina, the images you see may be blurry.


Seeing

Nearsightedness affects males and females equally. People who have a family history of nearsightedness are more likely to develop it. Most eyes with nearsightedness are healthy, but a small number of people with severe myopia develop a form of retinal degeneration.

  • Reviewed last on: 7/28/2010
  • Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine; and Franklin W. Lusby, MD, Ophthalmologist, Lusby Vision Institute, La Jolla, California. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Olitsky SE, Hug D, Smith LP. Abnormalities of refraction and accommodation. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 619.

Wilkinson PS, David EA, Hardten DR. LASIK. In: Yanoff M, Duker JS, eds. Ophthalmology. 3rd ed. St. Louis, Mo: Mosby Elsevier; 2008:chap 3.5.

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