Iris color and cataract: the Blue Mountains Eye Study

PURPOSE: To investigate the relationship between eye color and cataract. METHODS: A population-based cross-sectional study (N = 3654) was conducted near Sydney, Australia. Lens photographs were graded for cortical, nuclear, and posterior subcapsular cataract. Iris color was assessed at slit-lamp examination by comparison with four photographic standards. RESULTS: Eyes with dark brown irises were more likely to have nuclear (adjusted odds ratio, 1.59; 95% confidence interval CI], 1.03 to 2.28) or posterior subcapsular cataract (adjusted odds ratio, 2.50; 95% CI, 1.57 to 3.98) than eyes with lighter-colored irises. CONCLUSIONS: People with dark brown eyes are at increased risk of cataract and should be encouraged to protect their eyes from direct exposure to sunlight.