At least half of all blindness in the world is preventable. The International Agency for the Prevention of Blindness (IAPB), with its national and international partners, seeks to reduce the global toll of 40 million blind people by increasing awareness of this problem among the people of the world and their governments, by encouraging financial and manpower support of blindness prevention programs, and by promoting the development of effective prevention programs employing the most appropriate and economic technology. This volume is based on the proceedings of the Third General Assembly of the IAPB held in New Delhi in December 1987. It provides up-to-date information on the four main causes of blindness--trachoma, xerophthalmia, onchocerciasis, and cataract--and sets out the strategies for dealing with them in different regions of the world. There are also reports and recommendations from all the major organizations devoted to the prevention of blindness.