Nearsightedness: Up close vision is good, while distant sight is blurry
In the normal eye, light rays pass through the cornea (clear front portion of the eye), through the lens, and are focused on the retina (back portion of the eye). Once focused on the retina, information is transmitted by millions of tiny nerve bundles via the optic nerve to the brain, where these images are translated into what we know as "sight."
Of course this is a very basic and somewhat simplistic explanation of how we see. There are a number of reasons for poor vision, but the most common are "refractive errors": the light rays that ideally should be focused on the retina converge in front of or behind the retina.
When light rays are focused in front of, instead of on, the retina, we describe this condition as myopia, or nearsightedness. When the light rays are focused behind the retina, then hyperopia, or farsightedness, results.
Refractive errors may be corrected with glasses or contact lenses to give the wearer good vision by changing the way light is focused on the retina.
To surgically correct myopia, or nearsightedness, the cornea must be flattened. Laser correction of certain visual problems is the most technologically advanced method available today to reduce your dependence on glasses and contact lenses. The outpatient procedure can correct nearsightedness, farsightedness, and astigmatism by gently reshaping the front surface of your eye with a cool, ultraviolet beam of laser light.
It is estimated that over one million laser procedures have been performed in 52 countries around the world. In fact, laser vision correction is expected to become the most common procedure performed worldwide within the next three years.