If the curvature of your cornea or lens varies from normal, or your eye is longer or shorter than normal, light will not focus sharply on your retina. These conditions create what is called a refractive error, which results in blurry vision.
Variations in the shape of the cornea may create nearsightedness (myopia), farsightedness (hyperopia) or a mild imperfection in the curvature of your cornea that can cause distorted, blurry vision (astigmatism). As a natural part of aging, people older than 40 gradually lose the ability to focus on nearby objects (presbyopia).
Eye tests assess visual function, refractive errors, eye muscle balance, and the presence or absence of glaucoma, corneal disease, retinal disease, and cataract. Refractive errors can be corrected with glasses, contact lenses or surgery, including laser eye surgery.
Why choose Mayo Clinic for eye care
Mayo Clinic in Rochester, Minn., is ranked among the Best Hospitals for ophthalmology by U.S. News & World Report.
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