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Lifespan’s A - Z Health Information Library |
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Normal, nearsighted, and farsighted vision Normal vision occurs when light is focused directly on the retina rather than in front or behind it. A person with normal vision can see objects clearly both near and faraway. Nearsightedness results in blurred vision when the visual image is focused in front of the retina, rather than directly on it. It occurs when the physical length of the eye is greater than the optical length. For this reason, nearsightedness often develops in the rapidly growing school-aged child or teenager, and progresses during the growth years, requiring frequent changes in glasses or contact lenses. A nearsighted person sees near objects clearly, while objects in the distance are blurred. Farsightedness is the result of the visual image being focused behind the retina rather than directly on it. It may be caused by the eyeball being too small or the focusing power being too weak. Farsightedness is often present from birth, but children can often tolerate moderate amounts without difficulty, and most outgrow the condition. A farsighted person sees faraway objects clearly, while objects that are near are blurred.  Review Date: 1/21/2009
Reviewed By: Paul B. Griggs, MD, Department of Ophthalmology, Virginia Mason Medical Center, Seattle, WA . Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. The information provided herein should not be used during any
medical emergency or for the diagnosis or treatment of any medical
condition. A licensed medical professional should be consulted for
diagnosis and treatment of any and all medical conditions. Call 911
for all medical emergencies. Links to other sites are provided for
information only -- they do not constitute endorsements of those
other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the
information contained herein is strictly prohibited.
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