[Tropical ophthalmology--prevention and therapy"Vision 2020--the right to sight"].

Worldwide 45 million people are blind, 180 million people are visually handicapped, 90% of all blind people are living in developing countries and 80% of blindness is preventable. The global economic productivity loss due to blindness was estimated to be 19 billion US$ in the year 2000. The initiative "Vision 2020-the right to sight" aims to increase the cataract surgical rate and to eliminate diseases such as trachoma and onchocerciasis as well as avoidable blindness in children. It is planned that blindness in 100 million people can be avoided by the year 2020.