OBJECTIVES: Cataract is a major cause of blindness and of severe visual impairment leading to bilateral blindness in an estimated 20 million people worldwide. In developing countries 50-90% of all blindness is due to cataract. There are several possible approaches to removal of the cataract. This paper reports estimates of the population health effects, costs and cost-effectiveness of selected interventions in cataract surgery to restore eyesight in areas of the world with different epidemiologic profiles. METHODS: Effectiveness estimates are based on literature review taking into account factors such as operative failure, complications and patient non-compliance. A population model was applied to follow to the life-long impact of individuals receiving cataract surgery. Costing estimates are based on primary data collection in 14 epidemiological sub-regions by regional costing teams and literature review, and were estimated for different coverage levels using non-linear cost functions. RESULTS: Intra- and extra-capsular cataract surgery are cost-effective ways to reduce the impact of cataract-blindness. Extra-capsular cataract surgery is more cost-effective than intra-capsular surgery in all regions considered, and higher coverage levels are always more cost-effective than lower coverage levels. Extra-capsular cataract surgery at a 95% coverage level would avert over 3.8 million disability adjusted life years per year globally. The cost-effectiveness ranges from I$69 per DALY in SearD (South East Asian Region with high child and adult mortality) to I$2341 per DALY in WprA (Western Pacific Region with low child and adult mortality). CONCLUSIONS: In cataract surgery, extra-capsular surgery at high coverage level is the most cost-effective way for restoring eyesight.