Hiện nay con số này đang gia tăng khoảng một triệu mỗi năm tăng dân số và tuổi của thế giới. Khoảng 80% những người này sống tại các nước nghèo của phát triển Nếu xu hướng hiện nay tiếp tục, | 13 Cataaact surgery in che Third World The World Health Organisation WHO estimates that there are 20 million people blinded by cataract which is approximately 45 of all blindness Figure . At present this number is growing by about one million per year as the world s population increases and ages. Around 80 of these people live in the poor countries of the developing If present trends continue it is estimated that by 2020 there will be 75 million blind people in the world of whom 50 million will be blind from Currently there are approximately ten million cataract operations per year of which about four million are carried out in Third World To avoid a massive increase in cataract blindness the number of operations must grow to 32 million per This requires an increase in the number of cataract operations of about 7 per year. Virtually all of this increase must take place in Third World countries. As well as extracting a terrible cost in terms of human suffering cataract has major economic implications. It has been estimated that the cost of blindness in India is more than four billion dollars every year. Approximately half of this cost is due to The cataract surgical rate CSR namely the number of operations per million people per year is a simple measure of the delivery of cataract surgery to a population. Currently the CSR varies from over 5000 in parts of North America to less than 100 in some African Figure This woman had been blind for at least two years when she came to an eye clinic in Beletwein Somalia. She had travelled for more 200 km in order to have cataract surgery. Her situation is typical of the millions who are blind from cataract today. countries. The CSR needed to eliminate cataract blindness will vary according to the number of elderly people in a population and the perceived visual requirements of that population but it is thought that the minimum required is about 2000 operations per .
