Nearsightedness is a condition where the patient can see near objects, but has difficulty seeing objects far away. If you are nearsighted, your eye focuses light in front of the retina, instead of on it. This is caused by either the shape of your cornea being to curved, your eyeball being too long, or a combination of both. To correct nearsightedness, eye doctors prescribe a lens (glasses or contacts) that reduce the eye’s focusing power (-) and enables light to focus more closely to the retina.
The lasik eye surgery (or laser eye
surgery) to correct nearsightedness involves the use of an excimer laser to remove microscopic cells from the center of the cornea. The procedure effectively flattens out the shape of the patients’ cornea, thus reducing its refractive power. The result
after lasik eye surgery is that when light enters the eye it is no longer converged at a focal point in front of the retina, but on or closer to the retina.
Farsightedness (Hyperopia)-
Farsightedness is a condition where the patient can see far objects, but has difficulty seeing objects up close. If you are far sighted, your eye focuses light behind the retina. This is caused by either the shape of your cornea being too flat, your eyeball being too short, or a combination of both. To correct farsightedness, eye doctors prescribe a lens (glasses or contacts) that increases the eye’s focusing power (+) and enables light to focus more closely to the retina.
The lasik eye surgery (or laser eye
surgery) to correct farsightedness involves the use of an excimer laser to remove tissue from the outer parts of the cornea. The procedure effectively makes the shape of the patients’ cornea more acute, thus increasing its refractive power. The result
of lasik eye surgery is that light is no longer converged at a focal point behind the retina, but on or closer to the retina.
Astigmatism-
Astigmatism is a condition in which the patient has trouble seeing objects up close and far away. Images often appear blurry, or in double. If you have astigmatism, your eye does not converge light into one single focal point. Instead of being round like a tennis ball, an astigmatic eye is shaped more like a football. The cornea is more steeply curved in one direction than it is the other. To correct astigmatism, eye doctors prescribe “cylindrical lenses” which are specially crafted to refract light differently on different parts of the eye. The custom lens converges light traveling through unequal parts of the eye into one focal point on the retina.
The lasik eye surgery to correct astigmatism involves the use of an excimer laser to remove selected corneal tissue. The procedure smoothes out the curvature of the cornea by removing tissue from selected locations. The result
of lasik eye surgery is that light is refracted uniformly from the cornea and converged to a single focal point on or close to the retina.
Common Vision Problems:
