The distributions of spherical equivalent residuals were plotted for each observed genotype at rs634990 of GJD2 (left) and rs150094 of PRSS56 (right). After adjusting for age, sex, years of education, nuclear sclerosis and the first two principal components, (A) each copy of the minor allele C of rs634990 is associated with a 0.29 D decrease in spherical equivalent (p = 1.8 × 10^-3), and (B) the minor allele G of rs150094 is associated with a 0.33 D decrease in spherical equivalent (p = 1.7 × 10^-3). To access the data, click or select the words “Appendix 4.”