COMPUTERIZED VIDEOKERATOSCOPES DATA DISPLAY Curvature Maps There are a number of things that can be changed to make the maps look different. The map can look different depending on how much difference in dioptric value occurs between colors. The accompanying photos show the same data from a cornea plotted with 0.50 D. and 0.25 D. steps between colors. The maps appear quite different even though it is the same data. Therefore, when comparing maps one must determine the dioptric step value between colors.