Movement up the household energy ladder from smoke-producing biomass fuels indoor air pollution to relatively clean liquid, gaseous and electric fuels is commonly part of the econcooking smoke omic transition and thus plays a role in the accompanying health transition. Here, biomass we analyse the relationship between type of cooking fuel and the prevalence health of partial and complete blindness in India using data on 173 520 persons age 30 blindness and over from the 1992-93 National Family Health Survey. Logistic regression is eye disease used to estimate the net effects of biomass fuel (wood or dung) use on preva-India lence of partial and complete blindness after controlling for availability of a separate kitchen, house type, crowding, age, gender, urban-rural residence, education, religion, caste/tribe and geographical region. Persons living in biomass fuel-using households are found to have a considerably higher prevalence of blindness (partial or complete) than those living in households using cleaner fuels (OR 1.32; 95% CI 1.16-1.50). The effects are large and statistically significant for both men (OR 1.31; 95% CI 1.12-1.52) and women (OR 1.30; 95% CI 1.12-1.50) and for urban areas (OR 1.22; 95% CI 1.01-1.49) and rural areas (OR 1.49; 95% CI 1.23-1.80). The effects are strong and significant for partial blindness (OR 1.34; 95% CI 1.17-1.53), but not for complete blindness (OR 1.09; 95% CI 0.79-1.51). The level of risk and extent of biomass fuel use in India indicate that 18% of partial and complete blindness among persons age 30 and older may be attributed to biomass fuel use. The results strongly suggest that smoke exposure from the use of biomass fuels for cooking substantially increases the risk of partial blindness.