The images below are of the same eye. This eye underwent Radial Keratotomy (RK) 30 years ago. 15 years later this same eye underwent LASIK surgery. A special dye was used to highlight the corneal defects created by these surgeries. In the first photo, note the lite up radial lines. These are the still open RK cuts or incisions. Note the circular yellow green line going around the periphery of the cornea. This is the border of the LASIK flap. The bright green horizontal line going across the lower portion of the cornea is known as a “cross cut incision” intended to eliminate any astigmatic error. The fact that these defects “lite up” tell you that these incisions are still open and subject to infection from opportunistic organisms entering these defects. The 2nd image was taken with a computerized corneal topographer. This technology involves casting lit concentric rings at the cornea. These rings reflect back into the computer-camera so that a photo can be taken. If the cornea had a smooth undistorted surface, the rings would appear to be perfectly round. Note how distorted these rings are. It is for this reason that eyeglasses and regular contact lenses cannot correct the vision in this eye. A scleral lens, however, will replace this cornea as an optical surface and allow the patient to see clearly once again.