Estimates from population-based surveys in multiple countries suggest that many adults aged 50 and older who are facing cataract-related blindness still need access to surgical treatment. Reports indicate that roughly half of those affected may require surgery, although the exact number is not specified. The issue of cataract surgical coverage is being studied in various countries, including Kenya, Nepal, and India, with some research also exploring related topics such as refractive error coverage and access to surgical services.