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farsightedness
(redirected from presbyopia)

   Also found in: Dictionary/thesaurus, Medical, Wikipedia, Hutchinson 0.15 sec.
farsightedness or hyperopia, condition in which far objects can be seen easily but there is difficulty in near vision. It is caused by a defect of refraction in which the image is focused behind the retina of the eye eye, organ of vision and light perception. In humans the eye is of the camera type, with an iris diaphragm and variable focusing, or accommodation. Other types of eye are the simple eye, found in many invertebrates, and the compound eye, found in insects and many
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 rather than upon it, either because the eyeball is too short or because the refractive power of the lens is too weak. Presbyopia, a similarly faulty vision, is attributable to physiological changes in the lens brought on by age. Corrective eyeglasses with convex lenses compensate for the refractive errors.


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Key statement: Correction of eye refractive errors like presbyopia, hyperopia, myopia and astigmatism using either pre-tensioned or transcutaneously energized artificial muscle implants.
But they also correct presbyopia, the declining ability to see things up close.
The newly developed lens is "the only adaptive lens that is practical for presbyopia patients,' says biomedical and optical engineer Shuliang Jiao of the University of Miami (Fla.
 
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