Inter-ocular differences (mean±SE) in spherical equivalent (M), most myopic meridian (MMM), most hyperopic meridian (MHM), refractive (RA), corneal (CA), and internal astigmatisms (IA) for the control group and a subset of birds from the treatment groups (remark: n = 8 in each group) with both refractive and corneal measurements.

Note that the astigmatic axes in the last three rows are calculated by circular statistics (mean±angular deviation) for the treated eyes only. In experiment A, the comparisons across the controls and treated groups were tested by one-way ANOVA followed by Tukey’s test. In experiment B, the comparisons between high and low magnitudes of imposed astigmatism were tested by two-sample t-tests. The levels of significant difference are indicated by asterisk: * p≤0.05, ** p≤0.01, *** p≤0.001 in experiment A, and # p≤0.05, ## p≤0.01, ### p≤0.001 in experiment B. Comparisons for the astigmatic axis were performed by Watson-Williams F-tests followed by pairwise comparison tests. a Experiment A b Experiment B Inter-ocular differences (mean±SE) in spherical equivalent (M), most myopic meridian (MMM), most hyperopic meridian (MHM), refractive (RA), corneal (CA), and internal astigmatisms (IA) for the control group and a subset of birds from the treatment groups (remark: n = 8 in each group) with both refractive and corneal measurements.