Data from the Hispanic Health and Nutrition Examination Survey and the National Health and Nutrition Examination Survey I were analysed to determine the prevalence of visual acuity impairment among US Hispanics and non-Hispanics aged 6-19 years. The prevalence of 20/30 or worse distance visual acuity with usual or habitual correction ranged from 10.8% in non-Hispanic whites to 19.1% in Puerto Ricans. Puerto Rican boys aged 13-19 years had significantly greater rates of moderate or greater impairment (20/70 or worse) than 6-12-year-old Puerto Rican boys (5.7% vs. 0.7%). The prevalence of visual impairment was generally greater in girls than in boys. Assessment and comparison of refractive error and eye disease prevalence rates are necessary in future studies to determine factors influencing prevalence of visual acuity impairment in children.