Fig. 3. If the diameter is held constant, by decreasing the radius of curvature from 8.4 to 7.8 mm, the sagittal height or vault of the lens is increased. (Stein HA, Slatt BJ: Fitting Guide for Rigid and Soft Contact Lenses: A Practical Approach, 2nd ed. St. Louis, CV Mosby, 1984)