Myopia, my OH pee uh, also called nearsightedness or shortsightedness, is a visual defect that causes blurred distance vision. Except in extreme cases, near vision remains clear. For the eye to form a clear image, the light rays reflected or given off by an object must come together on the retina, the light-sensitive tissue lining the back and sides of the eyeball. In most people with myopia, the eyeball is longer than normal from front to back. As a result, light rays from a distant object meet in front of the retina. When the rays do strike the retina, they form a blurred image.