Figure 2.

Higher-order root mean square (HO RMS) wavefront error (WFE) across the three corrections for (A) the mean of all eyes and (B) all individual eyes. Error bars are one standard deviation. In (B) two eyes of a subject are plotted in the same color; right eyes solid; left eyes dashed; symbols indicate severity grade of posterior radius of curvature.³³ The 95% limits for normal eyes (Salmon and van de Pol⁴⁴) are plotted as well as mean levels for eyes with keratoconus wearing conventional scleral lenses (Gumus et al.⁶) and wavefront-guided scleral lenses (Sabesan et al.¹⁴). Study data is scaled⁴³ in the Discussion for comprehensive comparison with literature; here available data for contact lens related norms have been approximated to a common 5mm using the ratio of pupil sizes.