Myopia can cause severe visual impairment. Here, we report a two-stage genome-wide association study for three myopia-related traits in 9,804 Japanese individuals, which was extended with trans-ethnic replication in 2,674 Chinese and 2,690 Caucasian individuals. We identify WNT7B as a novel susceptibility gene for axial length (rs10453441, P-meta = 3.9 x 10(-13)) and corneal curvature (P-meta = 2.9 x 10(-40)) and confirm the previously reported association between GJD2 and myopia. WNT7B significantly associates with extreme myopia in a case-control study with 1,478 Asian patients and 4,689 controls (odds ratio (OR)(meta) = 1.13, P-meta = 0.011). We also find in a mouse model of myopia downregulation of WNT7B expression in the cornea and upregulation in the retina, suggesting its possible role in the development of myopia.