In 1990, the WHO Programme for the Prevention of Blindness estimated that there were 13.5 million unoperated cases of cataract in the world. More than 95% of this backlog is found in developing countries. A conservative estimate of incidence of blindness due to cataract as 1/1000 population/year demonstrates that most developing countries are still unable to provide cataract surgery to the annual load of new cases. The situation is particularly worrying in Africa, south of the Sahara, where only one out of ten cataract ever gets operated on. The WHO Programme has developed a primary health care strategy for the large-scale management of cataract. Identification of cases requiring surgery should be possible at the community level, through training of auxiliary staff. Referral for surgery at the district or province hospital level is possible in most cases, given manpower development. This implies a need for training of cataract surgeons in many developing countries. There should be one cataract surgeon per 250,000 population. Increasing surgical 'productivity' of existing ophthalmologists should be considered as well as improving management of intervention programmes.