Presbyopia is a naturally occurring type of farsightedness in which the ability to see close objects clearly is reduced as people get older.
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As many adults pass age 40 or so, they find that it becomes harder to read newspapers and books. They start to hold these items farther away from their eyes than they had in the past, because they are trying to bring the print into focus. Eventually, as the joke goes, they find that their arms are too short. This condition is called presbyopia (pres-be-O-pe-a), which is from the Greek words meaning "old eyes." The condition causes a person to become slightly farsighted.
Normally, small muscles bend the clear lens at the front of the eye-ball to focus a close image, like the words on this page. But as a person reaches his thirties and forties, the lens loses its elasticity and becomes too thick and too rigid to flex easily. This causes presbyopia.
The first sign of presbyopia usually occurs when people find that they cannot read small print as easily as they did in the past. Their eyes may feel tired more quickly, or they may develop headaches during close work. Eventually, many people need eyeglasses for reading.
People who are already farsighted will need to see their ophthalmologists * if they notice these symptoms, as they will probably need stronger prescription eyeglasses to read. For people with nearsightedess, presbyopia may seem at first to help their vision. That is because for them, the condition changes how close images are focused in a way that makes them clearer. This is sometimes called "second sight," and people with nearsightedness sometimes find for a time that they do not need their eyeglasses to read. Eventually, though, they will need eyeglasses or perhaps bifocals * to read properly.
* ophthalmologist is a medical doctor who specializes in treating diseases of the eye.
* bifocals or multifocal (progressive) lenses are prescription eyeglasses that have lenses divided into two or more sections. The bottom section allows a person to see things clearly that are close, and the top section allows a person to see things clearly that are far away
The U.S. National Eye Institute, one of the National Institutes of
Health, posts a resource list of eye health-related publications and
organizations at its website.