Figure 2

Single-angle polar plots for the (A) target induced astigmatism vector, (B) surgically induced astigmatism vector, (C) difference vector, and (D) correction index at the axis of target induced astigmatism vector at 3 months postoperatively are shown. The mean absolute of vectors and the centroid of vectors calculated in double-angle vector space are displayed in the call-out box. Cyl, cylinder; Arith, arithmetic; D, diopters; Ax, axis.