One embodiment of the present invention is a method for providing a deviation map of an eye that includes: (a) acquiring data comprising a corneal topographic map; (b) determining locations of abnormal curvature within the topographic map; (c) determining a modified topographic map by removing data associated with locations of abnormal curvature; (d) computing a reference map from the modified topographic map; (e) computing a deviation map by combining the topographic map and the reference map; and (f) displaying or storing the deviation map. An additional embodiment includes the processing of pachymetric data in a similar fashion.