(a)
(b)
(c)
Figure 2: Double-angle plots of preoperative, 12-week postoperative, and surgically induced astigmatism. Coordinates of the preoperative astigmatism (a) are more clustered around its centroid value than the 12-week postoperative astigmatism (b) and the SIA (c). The coordinates are shown in red and the centroid value is shown in blue.