Figure 2: Optical quality parameters with 2, 4, and 6mm pupil sizes at each diopter of astigmatism. (a) Mean modulation transfer function (MTF) cutoff frequency. (b) Mean Strehl2D ratio. Each parenthesis means values of the standard deviations. Repeatedmeasures analysis of variance, followed by the Dunnett post hoc test for multiple comparisons, was used to compare the differences between groups with different pupil sizes: c/deg = cycles per degree, D = diopter. 
