Global trends in the magnitude of blindness and visual impairment
The first global estimate on the magnitude and causes of visual impairment was based on the 1990 world population data (38 million blind). This estimate was later extrapolated to the 1996 world population (45 million blind), and to the projected 2020 world population (76 million), indicating a twofold increase in the magnitude of visual impairment in the world by 2020. It provided the basis for the 1999 launch of VISION 2020, the Global Initiative for the Elimination of Avoidable Blindness.
The extent of the global burden of visual impairment in 2002 is not strictly comparable to the previous estimates of 1990, which indicated there were 148 million visually impaired, of which 38 million were blind. While the 2002 world population has increased by 18.5% as compared to 1990, the population 50 years of age and older has increased by nearly 30%. The population increase is more prominent in developing countries. Taking into account the changes in world population over the past 12 years, the extent of blindness and visual impairment in 2002 appears to be lower than was projected – 37 million instead of the projected 52 million.
It is likely that the change is due to two major factors:
- More data from population based studies on visual impairment carried out over the last decade are available allowing for more accurate estimates to be made. ¨
- Significant achievements have been made in the prevention and management of avoidable blindness along the lines of the "VISION 2020: The Right to Sight" priorities.
- Increased public awareness and utilization of eye health care services
- Increased availability and affordability of eye health care services
- Increased global political commitment to prevention of visual impairment
- Increased professional commitment to prevention of visual impairment
- Commitment and support of non-governmental organizations
- Involvement and partnership with the corporate sector
- More effective primary eye care activities as an integral part of the primary health care system which have contributed to the decline in vision loss from trachoma, onchocerciasis, vitamin A deficiency and even from cataract through better services including outreach case finding and eye health education.
- Impressive successes with elimination of blindness efforts in the Gambia, India, Morocco, Nepal, Sri Lanka, Thailand, and other countries.
Poverty underlies not only the causes, but also the perpetuation of ill health, including eye health. Blindness remains a key barrier to development. Health is the centrepiece of development and poverty alleviation; continuing to eliminate avoidable blindness among the poorest of the poor is a moral imperative
An ever-increasing number of people are at risk of visual impairment as populations grow and demographic shifts move towards the predominance of older age groups.
Potentially blinding eye conditions such as age-related macular degeneration (AMD), diabetic retinopathy and glaucoma are increasing as the number of people affected grows. These are non-communicable chronic eye diseases to which the principles of long-term care including issues of cost of treatment and compliance (adherence) apply. Additionally, more programmes for those with low vision will need to be made available.
The global disparity and inequity in the availability of eye health care services still fails to prevent and control an overwhelmingly increasing magnitude of avoidable blindness in the highly populated poorest parts of the world.