When the shape of the eye is too long, light rays focus in front of the retina instead of directly on it. Under these circumstances, near objects are perceived clearly but distant objects are not.
LASIK, PRK, ICLs, or cataract surgery can be used to treat nearsightedness.
How the Eye Works
The eye’s surface, or the cornea, is convex. A well-shaped cornea allows light rays that hit it to bend through the pupil, pass through the lens, and focus precisely on the retina at the back of the eye. The retina converts the light rays into electrical impulses that are sent through the optic nerve to the brain, where a clear image is produced.