What is Astigmatism?

In the normal eye, light traveling through the cornea in both the horizontal plane and vertical plane is refracted (bent) the same, so that the image is properly focused on the retina in the back of the eye. Vision is clear. With astigmatism, an abnormal curvature of the cornea in one direction causes light traveling in one plane, the horizontal plane in this case, to be focused in front of the retina. The light striking the retina through the horizontal plane is out of focus on the retina and vision is unclear.

The Treatment

Laser in-Situ Keratomileusis (LASIK) can be used to treat some cases of regular astigmatism. Astigmatism occurs when the shape of the cornea is irregular, and not spherical in shape. This causes light rays in one axis to be focused away from the retina, resulting in blurred vision. LASIK uses the computer-controlled precision of the excimer laser to treat the inner tissue of the cornea in one direction more than the other.

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The procedure is done using eye drop anesthesia, and, while you may feel pressure, the technique is generally not painful. First, an instrument known as a microkeratome makes a protective flap in the outer layer of the cornea, at about twenty-five percent of its depth from the surface. Next, the excimer laser sculpts the internal corneal tissue to the correct refractive power in the “steep” axis by flattening the curvature of the exposed corneal tissue in that axis more than the other. Light rays are then more directly focused on the retina in both axis, thereby reducing the astigmatism. After a few minutes of drying, the corneal flap is laid back in its original position. Due to the cornea’s extraordinary natural bonding qualities, the flap seals on without sutures within two to five minutes. The surgery is performed on an out-patient basis and most people return to work within one to three days. As with any surgical procedure, individual results cannot be guaranteed and side effects and complications may occur.

The Result

Before LASIK treatment, light traveling in the horizontal meridian is out of focus on the retina. After LASIK treatment, the reshaped cornea causes light to bend in such a way as to become focused on the retina. Vision is clear.

We offer FREE Consultations and Seminars about LASIK. Contact us at (630)-833-9621 for details concerning the next available date.