A population-based cross-sectional survey of 838 men aged 30 years and over was conducted to examine the effect of aspirin, and other potential risk factors, on the prevalence of cataracts. Lens opacities were graded on clinical examination for location (cortical, nuclear, and posterior or subcapsular) and severity. The results do not support the claim that large doses of aspirin, or frequent use of aspirin, protects against or retards the growth of lens opacities.