Socio economic aspects of blindness and visual impairment
An analysis of the global distribution of visual impairment shows a disproportionately large prevalence in low-income developing countries. In these countries cataract and trachoma are the greatest causes of avoidable blindness. The lack of and inequity of access to prevention and eye care services severely limit in these regions of the world, the benefits that can be realized by modern medical advancements.
Quality-Adjusted Life Years
The lack of economic development is a factor that aggravates the prevalence of visual impairment. For this reason, blindness prevention programmes must concern themselves not only with the elimination of avoidable blindness but also with concurrent economic development. The costs of rehabilitation and care provided to the visually impaired are the most obvious. Less apparent but just as significant, however, are the indirect costs resulting from the loss of productivity.
To calculate the economic burden of visual impairment, including prevention and care, economists often use a cost-effectiveness ratio to which is added an efficiency indicator weighted by an expression of the quality of life. This is commonly expressed as an additional yearly cost required for survival adjusted for the quality of life. Eye health programmes focusing on prevention of blindness and care of the visually impaired have elevated QALYs.
Fore more information: WHO documents
- The magnitude and cost of global blindness [pdf 111kb]
- Trachoma-related visual loss [pdf 228kb]
- Prevention of blindness and priorities for the future [pdf 189kb]
Cost-effectiveness analysis of cataract surgery: a global and regional analysis
- Assessing the environmental burden of disease
For more information: non WHO documemts
Disability-Adjusted Life Years (DALY)
The visually impaired person and his/her family face serious social challenges. Directly and indirectly visual impairment interferes with many daily activities. In the case of adults, the possibilities for gainful employment are severely limited as is their participation in many activities. To this is often added a loss of social status and self esteem. The physical limitations and psychosocial implications of visual impairment cannot be measured in exact monetary terms. Nevertheless, it is clear that they diminish the quality of life not only for blind persons, but for their families as well.
A method for calculating the losses and gains of life expectancy due to prevention, care and eventual rehabilitation in the case of visual impairment uses a derived measurement called a DALY, which comprises 5 variables. The DALY combines in one measure the time lived with disability or poor health and the time lost due to premature mortality. One DALY can be thought of as one lost year of 'healthy' life and the burden of disease as a measurement of the gap between current health status and an ideal situation where everyone lives into old age free of disease and disability.