Farsightedness

Sometimes an eye is too small, or the cornea is flatter than it should be. The result is that objects seen close up are blurry, while objects seen at a distance are viewed normally. The name for this is farsightedness--or hyperopia.

Here's what happens when you have hyperopia: When light rays enter the eye, the rays are bent by the cornea (lens) and focused on the back of the eye (retina). When the eyeball is flattened, however, light focuses in back of the retina, rather than on it. This focusing problem is what eye-care specialists refer to as a "refractive" defect.

Eyeglasses or contact lenses easily correct the problem by refocusing the image on the retina. They do so with a lens that is convex on both surfaces.

In recent years, eye surgery has also become an option for correcting farsightedness. LASIK, which stands for "laser in situ keratomileusis," has been performed in the United States since the early 1990s. It uses a tiny laser beam to "shave" off a minute amount of eye tissue to correct the vision defect.

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