[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Luxi County of Yunnan Province: the China Nine-Province survey].

Objective: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Luxi County of Yunnan Province, China.

Methods: It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5575 individuals aged ≥ 50 years in Luxi County.