AIM: To estimate the prevalence and causes of blindness in children in the southern Indian state of Andhra Pradesh. METHODS: These data were obtained as part of two population based studies in which 6935 children <or=15 years of age participated. Blindness was defined as presenting distance visual acuity <6/60 in the better eye. RESULTS: The prevalence of childhood blindness was 0.17% (95% confidence interval 0.09 to 0.30). Treatable refractive error caused 33.3% of the blindness, followed by 16.6% due to preventable causes (8.3% each due to vitamin A deficiency and amblyopia after cataract surgery). The major causes of the remaining blindness included congenital eye anomalies (16.7%) and retinal degeneration (16.7%). CONCLUSION: In the context of Vision 2020, the priorities for action to reduce childhood blindness in India are refractive error, cataract related amblyopia, and corneal diseases.