Global Look at Visual Impairment
Lancet Global Health
Bourne et al. set out to provide world-wide estimates, trends, and projections of vision impairment and visual loss. They found mixed results: On one hand, the age-standardized prevalence of visual impairment and loss continue to decline. On the other, however, the overall growth in population—and the aging of that population—is contributing to a substantial increase in the number of people affected.
For this meta-analysis, the researchers updated an earlier report, for a total of 288 population-based studies contributing data from 98 countries. Of the 7.33 billion people alive in 2015, an estimated 36 million (crude prevalence 0.48%) were blind (defined as visual acuity [VA] worse than 20/400), 216 million had moderately and severe impaired VA (between 20/400 and 20/60), and 188 million had mildly impaired VA (between 20/60 and 20/40).
For the first time, there was enough information on presbyopia for the researchers to complete a meaningful analysis of the condition. They estimate that 666.7 million people ≥ 50 years of age and 1.09 billion people ≥ 35 years of age are affected by uncorrected presbyopia.
Most of those who had the poorest VA resided in south Asia, east Asia, and Southeast Asia; and the age-standardized prevalence of blindness was highest in south Asia, western sub-Saharan Africa, and eastern sub-Saharan Africa. In addition, more women than men were visually impaired.
The findings highlight the need to scale up current efforts to improve vision, the researchers said, given the impact that visual acuity has on quality of life and economic security.
The original article can be found here.