Prevalence and correction of near vision impairment at seven sites in China, India, Nepal, Niger, South Africa, and the United States.

PURPOSE: To estimate the prevalence of near vision impairment and use of corrective spectacles among middle-aged and older adults in different settings and ethnic groups.
DESIGN: Population-based, cross-sectional study.
METHODS: People aged ≥ 35 years were randomly selected with cluster sampling in 4 rural settings in Shunyi (China), Kaski (Nepal), Madurai (India), and Dosso (Niger); 1 semi-urban area in Durban (South Africa); and 2 urban settings in Guangzhou (China) and Los Angeles (USA). Near visual acuity (VA), with and without presenting near correction, was measured at 40 cm using a logMAR near vision tumbling E chart. Subjects with uncorrected binocular near VA ≤ 20/40 were tested with plus spheres to obtain the best-corrected binocular VA.
RESULTS: A total of 17 734 persons aged ≥ 35 years were enumerated and 14 805 (83.5%) were examined. The age- and sex-standardized prevalence of uncorrected near vision impairment (VA ≤ 20/40) ranged from 49% in Dosso to 60% in Shunyi and Guangzhou, 65% in Kaski and Los Angeles, and 83% in Madurai and Durban. The prevalence of near vision impairment based on best-corrected visual acuity was less than 10% in Guangzhou, Kaski, Durban, and Los Angeles, but as high as 23% in Madurai. In multiple logistic regression models, uncorrected near vision impairment was associated with older age (odds ratio [OR] = 1.14, P < .001) and female sex (OR = 1.12, P = .027), but not with educational level (OR = 1.01, P = .812). Over 90% of people in need of near refractive correction in rural settings did not have the necessary spectacles. These rates were 40% in urban settings.
CONCLUSIONS: By 50 years of age, the majority of people suffer from near vision impairment, most of which can be corrected optically. Over 90% of those in need of near refractive correction in rural settings do not have the necessary spectacles.