Global Burden of Visual Impairment and Blindness

Vision loss and age-related eye diseases are major global public health problems. The Global Burden of Diseases, Injuries, and Risk Factors Study (hereafter referred to as the GBD Study) was commissioned by the World Bank in 1991 to provide a comprehensive assessment of the burden of 107 diseases and injuries, and 10 selected risk factors, for the world, specifically including data from 8 major regions. The methods of the original GBD Study (hereafter referred to as the GBD 1990 Study) created a common metric, the disability-adjusted life-year,1 which extends the concept of potential years of life lost due to premature death to include equivalent years of “healthy” life lost by virtue of being in poor health or disability. The number of disability-adjusted life-years caused by a disease or injury are calculated as the sum of the years of life lost due to premature mortality in the population and the years lost due to disability (YLD) for incident cases of the disease or injury.