Farsightedness (hyperopia) is the opposite of nearsightedness. It results when the eyeballs are too short or the lens is 100 weak (too convex). In the eyes of farsighted individuals, parallel light rays from distant objects usually fall into focus on the retina, but divergent rays from nearby objects cannot be focused sufficiently. Without corrective lenses, farsightedness individuals see distant objects well, but nearby objects are fuzzy. Glasses or contact lenses that bend the light inward bring near objects into sharp focus on the retina. Farsightedness is generally present from birth and tends to run in families. Nearsightedness (myopia) results when the eyeball is slightly elongated .Without corrective lenses; parallel light rays arising from distant images come into locus in front of the retina, creating a fuzzy image. In contrast, nearby images with much more divergent light rays lend to be in focus. People with nearsightedness, therefore, can see near objects without corrective lenses-hence the name. Nearsightedness may also result when the lens is too strong-that is too concave. This lens bends the light corning from distant objects too much, causing the image to come into focus in front of the retina. For all these problems Cary eye surgery or laser surgery is the best solution.
In lasik, the surgeon uses a special device to slice through the protective outer layer of the cornea-the clear dome over the front of the eye that admits light and allows, the eye to focus-to create a hinged flap. After folding back the flap to expose the cornea's inner layers, the surgeon uses a laser to reduce the corneal thickness to the degree calculated to correct the patient's vision. Then the flap is repositioned and the cornea quickly heals without stitches. It's an outpatient procedure requiring only local anesthesia.
Lasik evolved from PRK, or "photorefractive keratectomy," which also uses a laser to remove micro-thin layers of tissue from the cornea, but does not preserve the protective flap. Before PRK, surgeons modified the cornea by making spoke-like incisions that caused the cornea to flatten out, which usually improved the patient's vision, but often weakened the cornea itself. Though such procedures are still performed, lasik and PRK generally are considered superior because they arc more precise and cause less trauma to the eye. Laser Cary eye surgery is most often used for cases of myopia, or nearsightedness, which is correctable by reducing the thickness of the cornea. However, it also can correct hyperopia (farsightedness); and astigmatism, because both conditions are related to the curvature of the cornea.
