The primary function of your eye is to focus light. You need glasses or contacts when your eye cannot properly direct light rays on the retina. The cornea, at the front of your eye, provides most of the eye's focusing power. The lens inside your eye provides the fine tuning of light, contributing to your ability to read. Light rays must focus precisely on the retina for you to see clearly. If you wear corrective lenses, you may have one of the following common refractive problems:
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MyopiaMyopia (Nearsightedness) occurs when your eye is too long in relation to the curvature of your cornea. With myopia, near objects are seen more clearly than distant objects. |
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HyperopiaHyperopia (Farsightedness) occurs when your eye is too short in relation to the curvature of your cornea. With hyperopia, distant objects are seen more clearly than near objects. |
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AstigmatismAstigmatism occurs when your cornea is shaped like an oval. With astigmatism, more than one focal point within the eye distorts what you see. |
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PresbyopiaPresbyopia occurs as you reach your 40's or 50's. The lens inside your eye loses its elasticity, making it more difficult to read smaller print. Because laser vision correction does not deal with the lens of your eye, it can not correct this problem. |