The Scout Keratron is used by the Wave System to determine the exact curvature of your cornea. This instrument photographs the cornea while projecting a series of concentric rings on the corneal surface. Thousands of these data points are analyzed to create a topographical map of the cornea, capturing any variations that may be present. In the normal cornea this irregularity may reflect only the presence of astigmatism. Astigmatism is present in most eyes because the cornea is not totally spherical like the surface of a basketball, but rather shaped somewhat like a football.