Two cataract-free-zone projects, one in Brazil and the other in Peru, were designed to provide surgery to all those who need and want it within a defined geographic area. In-home visual acuity screening was accepted by three-fourths of the enumerated population aged 50 years or more. Those with reduced bilateral visual acuity were referred to a community health post for ophthalmic examination. Among those diagnosed as bilaterally blind (less than or equal to 20/200), comprising 5% of the screened population, two-thirds were thought to be blind from cataract. Because of other ocular pathology and general health conditions, surgery was not indicated for 30-50%. Two-thirds of those recommended for out-patient surgery accepted. Motivational efforts to convince the refusers were uniformly unsuccessful. The average age of those accepting and those refusing surgery was in the mid-seventies. Those already aphakic were 7-8 years younger. Post-operative acuity was greater than or equal to 20/50 for only one-half of those operated. A significant number of cases had previously undetected macular degeneration and other causes of decreased vision. These projects have given increased attention to cataract blindness and the need for further operational research to develop effective methods for its control using outpatient surgery.