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.
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.
A nearsighted person sees close up objects clearly, but objects in the distance are blurred. Squinting will tend to make far away objects seem clearer.
Signs and tests
A nearsighted person can easily read the Jaeger eye chart (the chart for near reading), but has trouble reading the Snellen eye chart (the chart for distance).
Wearing eyeglasses or contact lenses can help shift the focus of the light image directly onto the retina, producing a clearer image.
Early diagnosis of nearsightedness is important, because a child can suffer socially and educationally by not being able to see well at a distance.
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. – 7/28/2010