| Eye and Vision |
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Myopia
Also known as nearsightedness, myopia is the most common
refractive disorder. In North America, more than 70 million
people have myopia. This condition results from an eye being
too long, or a cornea that is too curved. In both cases,
light rays are focused in front of the retina and objects
in the distance appear blurred. |
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Hyperopia
Hyperopia, or farsightedness, is the opposite of myopia.
With hyperopia, the eye is too short, or the cornea is less
curved, resulting in light rays that focus behind the retina.
People with hyperopia experience blurred vision that is
worse at close range than far distances. Many people with
hyperopia also have astigmatism. |
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Astigmatism
Astigmatism occurs when the cornea is shaped like a football
with two different curvatures, producing two different focal
points. Images appear blurred or ghostly because light rays
are refracted unequally. In some cases, people experience
difficulty with both near and far vision. |
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Presbyopia
Associated with the natural aging process, presbyopia is
the hardening of the eye's natural lens. The result is reduced
elasticity, preventing the lens from focusing properly.
This is not a refractive disorder however, and cannot be
treated with Laser Vision Correction. But if the person
has myopia with presbyopia the effects may be reduced through
vision correction surgery. Known as monovision, the technique
leaves a small amount of myopia in one eye, allowing presbyopic
patients to maintain some near vision. |
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