A normal cornea is shaped like a perfect hemisphere (half circle) which starts the refraction process in the eye by directing light rays toward the lens. Astigmatism is an abnormally shaped cornea which causes the light rays to be scattered in different directions causing an uneven pattern of light rays to enter the eye. Either the curve of the cornea may be wrong or certain areas of the cornea might not conform to the same smooth curve.
If this condition is caused by genetics, it is usually present from birth and may worsen during eye development. Most astigmatic conditions develop during the growth years and will not advance later in life. Developing corneas usually remain astigmatic after they show the first signs of it, they do not usually fix themselves.
This condition often results in a slightly blurred or odd shaped image perception. If only portions of the cornea are affected, a distorted portion of the image will occur. If the shape of the whole cornea is wrong, the entire image will be distorted.
Young children will often experience near or far sighted conditions while their eyes are developing because the size of the eyeball, cornea, and lens may develop at slightly different rates. This often leads to confusion about the presence of astigmatism or the normal state of growth.
Mild cases of astigmatism can be corrected with glasses or contact lenses. If a portion of the cornea is affected, bifocal or trifocal lenses might help. More advanced cases can not easily be corrected with visual aids.
Advanced technology is improving the way that astigmatism is tested for. Opthahmologists have more tools available to measure the shape and quality of the cornea. There is also more options for vision aids to improve the quality of astigmatic sight.
Radial Keratotomy is a form of laser surgery which is used to correct many cases of astigmatism. The shape of the cornea can be modified to regain the smooth surface or curve it should have. Even with a successful treatment, people with advanced cases of astigmatism may still require glasses or contact lenses.
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