Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis
Authors: Rupert R A Bourne, Seth R Flaxman, Tasanee Braithwaite, Maria V Cicinelli, Aditi Das, Jost B Jonas, Jill Keeffe, John H Kempen, Janet Leasher, Hans Limburg, Kovin Naidoo, Konrad Pesudovs, Serge Resnikoff, Alex Silvester, Gretchen A Stevens, Nina Tahhan, Tien Y Wong, Hugh R Taylor, Rupert Bourne, Peter Ackland, Aries Arditi, Yaniv Barkana, Banu Bozkurt, TASANEE BRAITHWAITE, Alain Bron, Donald Budenz, Feng Cai, Robert Casson, Usha Chakravarthy, Jaewan Choi, Maria Vittoria Cicinelli, Nathan Congdon, Reza Dana, Rakhi Dandona, Lalit Dandona, Aditi Das, Iva Dekaris, Monte Del Monte, Jenny Deva, Laura Dreer, Leon Ellwein, Marcela Frazier, Kevin Frick, David Friedman, Joao Furtado, Hua Gao, Gus Gazzard, Ronnie George, Stephen Gichuhi, Victor Gonzalez, Billy Hammond, Mary Elizabeth Hartnett, Minguang He, James Hejtmancik, Flavio Hirai, John Huang, April Ingram, Jonathan Javitt, Jost Jonas, Charlotte Joslin, Jill Keeffe, John Kempen, Moncef Khairallah, Rohit Khanna, Judy Kim, George Lambrou, Van Charles Lansingh, Paolo Lanzetta, Janet Leasher, Jennifer Lim, Hans LIMBURG, Kaweh Mansouri, Anu Mathew, Alan Morse, Beatriz Munoz, David Musch, Kovin Naidoo, Vinay Nangia, MARIA PALAIOU, Maurizio Battaglia Parodi, Fernando Yaacov Pena, Konrad Pesudovs, Tunde Peto, Harry Quigley, Murugesan Raju, Pradeep Ramulu, Serge Resnikoff, Alan Robin, Luca Rossetti, Jinan Saaddine, MYA SANDAR, Janet Serle, Tueng Shen, Rajesh Shetty, Pamela Sieving, Juan Carlos Silva, Alex Silvester, Rita S Sitorus, Dwight Stambolian, Gretchen Stevens, Hugh Taylor, Jaime Tejedor, James Tielsch, Miltiadis Tsilimbaris, Jan van Meurs, Rohit Varma, Gianni Virgili, Jimmy Volmink, Ya Xing Wang, Ning-Li Wang, Sheila West, Peter Wiedemann, Tien Wong, Richard Wormald, Yingfeng Zheng
Journal: The Lancet Global Health (2017)

Global and regional prevalence estimates for blindness and vision impairment are important for the development of public health policies. We aimed to provide global estimates, trends, and projections of global blindness and vision impairment.We did a systematic review and meta-analysis of population-based datasets relevant to global vision impairment and blindness that were published between 1980 and 2015. We fitted hierarchical models to estimate the prevalence (by age, country, and sex), in 2015, of mild visual impairment (presenting visual acuity worse than 6/12 to 6/18 inclusive), moderate to severe visual impairment (presenting visual acuity worse than 6/18 to 3/60 inclusive), blindness (presenting visual acuity worse than 3/60), and functional presbyopia (defined as presenting near vision worse than N6 or N8 at 40 cm when best-corrected distance visual acuity was better than 6/12).Globally, of the 7·33 billion people alive in 2015, an estimated 36·0 million (80% uncertainty interval [UI] 12·9-65·4) were blind (crude prevalence 0·48%; 80% UI 0·17-0·87; 56% female), 216·6 million (80% UI 98·5-359·1) people had moderate to severe visual impairment (2·95%, 80% UI 1·34-4·89; 55% female), and 188·5 million (80% UI 64·5-350·2) had mild visual impairment (2·57%, 80% UI 0·88-4·77; 54% female). Functional presbyopia affected an estimated 1094·7 million (80% UI 581·1-1686·5) people aged 35 years and older, with 666·7 million (80% UI 364·9-997·6) being aged 50 years or older. The estimated number of blind people increased by 17·6%, from 30·6 million (80% UI 9·9-57·3) in 1990 to 36·0 million (80% UI 12·9-65·4) in 2015. This change was attributable to three factors, namely an increase because of population growth (38·4%), population ageing after accounting for population growth (34·6%), and reduction in age-specific prevalence (-36·7%). The number of people with moderate and severe visual impairment also increased, from 159·9 million (80% UI 68·3-270·0) in 1990 to 216·6 million (80% UI 98·5-359·1) in 2015.There is an ongoing reduction in the age-standardised prevalence of blindness and visual impairment, yet the growth and ageing of the world's population is causing a substantial increase in number of people affected. These observations, plus a very large contribution from uncorrected presbyopia, highlight the need to scale up vision impairment alleviation efforts at all levels.Brien Holden Vision Institute.