CYP19A1 and myopia: Our results reveal that synergistic interaction of rs6203 (HSD3B1), rs10046 (CYP19A1), and sex may confer susceptibility to high myopia; testosterone levels for either sex correlate significantly with high myopia; and rs605059 (HSD17B1) interacting with sex-related factors may be associated with circulating sex hormone levels in high myopia.