[A cross-sectional survey of blindness and visual impairment among adults in 13 regions of China from 2021 to 2022].

Objective: To investigate the prevalence of blindness and visual impairment in adults and the related causes in China. Methods: A population-based cross-sectional survey was conducted during 2021 and 2022 among 13 provinces, municipalities, and autonomous regions, including Beijing, Hebei, Jiangsu, Shanghai, Guangdong, Henan, Shanxi, Ningxia Hui Autonomous Region, Chongqing, Yunnan, Sichuan, Heilongjiang, and Liaoning. Respondents were adults aged 18 years and above, and were classified into groups of young adults (18 to 39 years), middle-age adults (40 to 59 years), and the elderly (≥60 years). The examinations included visual acuity measurement, non-contact tonometry, slit-lamp examination, fundus photography, automatic refraction (non-mydriasis), and demographics (questionnaire). The diagnosis and distribution of eye diseases were analyzed. The Cochran-Armitage test was used for statistical processing. Results: A total of 93 123 adults with a mean age of 48.8 years (range, 18 to 101 years) completed the survey, and the response rate was 76.2% (93 123/122 191). There were 37 725 males (40.5%) and 55 398 females (59.5%), while 32 357 (34.75%) were aged 18 to 39, 29 127 (31.28%) were aged 40 to 59, and 31 639 (33.97%) were aged≥60. According to the best-corrected visual acuity (BCVA) in the better eye of 93 123 adults, the blindness, moderate to severe visual impairment (low vision), and mild visual impairment were found in 280, 2 270, and 4 679 patients, respectively. Based on BCVA of the worse eye, the top three causes of blindness and low vision were cataract (1 271/2 982, 42.62%), uncorrected refractive error (433/2 982, 14.52%), and pathological myopia (90/2 982, 3.02%), without considering trauma or other undefined fundus diseases. Conclusions: From 2021 to 2022, the prevalence rates of blindness and low vision in Chinese adults were 0.30% and 2.44%, respectively. Cataract was the primary eye disease leading to blindness and low vision, and pathological myopia became the major cause of irreversible blindness in the population.