Definition: A condition common after age 40 in which a gradual lessening of the eye's power of accommodation causes difficulty in seeing near objects. Presbyopia is usually the cause of why people need reading glasses or bifocals after the age of 40.
Presbyopia
By Troy Bedinghaus, O.D., About.com
Updated: January 15, 2009
About.com Health's Disease and Condition content is reviewed by the Medical Review Board
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