 In 2010, 65% of 32 times 4 million blind people and 76% of 191 million people with MSVI worldwide had a preventable or treatable course, compared with 68% of 31 times 8 million and 80% of 172 million in 1990. Leading causes worldwide in 1990 and 2010 for blindness were cataract, 39% and 33% an uncorrected refractive error, 20% and 21% and macular degeneration. This article was authored by Dr. Professor Rupert R. A. Bourne, M.D., Gretchen A. Stevens, D.S.C., Richard A. White, Ph.D., and others.