MYOPIA is the medical term for nearsightedness. When a person is myopic, near objects
appear clear while distant objects are blurred. This is because the focusing power of the
eye is too long for the length of the eye.
Ideally, the cornea and lens, the two
focusing structures in the eye, focus images directly on the surface of the retina. If the eye is too long, or the focusing power too strong,
the image is focused in front of the retina. By the time the image gets to the retina, it
is blurred. Thus, the vision is blurred.
Corrective lenses in the form of glasses or contact lenses are used to refocus the
image so that it falls directly on the retina, clearing the vision.
There are now surgical procedures that can be done to permanently correct mild to
moderate amounts of myopia. Radial keratotomy and photorefractive keratectomy are
operations that reshape the cornea, and thereby correct its focusing power.