Astigmatism, which is not a disease, usually results when the cornea, the eye's front surface, develops an irregular curvature, and it is often linked with the problems of farsightedness and nearsightedness. When this condition exists, the way in which light rays within the eye are focused is disturbed, and steps should be taken to correct it.

If the abnormality is present and is not corrected, people's vision may resemble what we experience when we look into a wavy, distorted mirror at an amusement park or on the board walk at the beach. This indicates that the eye cannot focus light rays properly.

Using Eyewear to Correct Astigmatism

Two kinds of lenses are usually prescribed for correcting or improving the vision problems mentioned above:

• Eyeglasses add or subtract focusing power related to the cornea and lens of the eye.
  
  
• As the name implies, contact lenses are placed directly on the cornea, and they also add or subtract focusing power related to the cornea and lens.

Using Laser Surgery to Correct Astigmatism

Today, treatment of vision problems, such as astigmatism, includes some non-invasive surgical techniques. In line with this trend, the excimer laser is now the device of choice for eye surgeons whose patients require corrective surgery. With this procedure, the laser emits pulses of ultraviolet light that are used to correct the shape of the cornea while no energy is transmitted to the eye's internal tissues. Since virtually no heat is generated during surgery, there is minimal risk that the corneal tissues will be scarred.

The excimer laser is so precise that it would require approximately 200 pulses from the laser to cut through a single hair. When surgery is scheduled, a specific program, which is controlled with a computer, is created for every patient. It determines the number of pulses, surface area, and location that the laser light beam will impact, and tailored to the patient's particular vision correction needs.