Objective: To assess the prevalence and causes of visual impairment and blindness in adults living in an urban area of southern China. Methods: Random cluster sampling was used to identify the adults 50 years and older living in the Liwan district of Guangzhou, China. Presenting visual acuity (PVA) with habitual correction and best-corrected visual acuity (BCVA) based on autorefraction and subjective refraction were measured using the Early Treatment Diabetic Retinopathy Study visual chart.

more »

... dness and low vision were defined according to World Health Organization criteria. Eyes with visual impairment were assigned 1 principal cause for the impairment. Results: Visual acuity measurements were available for 1399 adults 50 years and older (75.3% participation rate). The prevalence of blindness and low vision based on the PVA was 0.6% (95% confidence interval, 0.2%-1.0%) and 10.1% (95% confidence interval, 8.5%-11.7%), respectively. These rates were reduced to 0.5% and 3.1% when the BCVA was considered. Based on the PVA, the principal causes for blindness were cataract (39.6%), glaucoma (11.0%), and myopic maculopathy (6.6%). The majority of low vision cases were attributable to cataract (45.3%) and uncorrected refractive error (43.9%). Conclusion: The majority of eye diseases leading to visual impairment are potentially treatable in this population.