Results: A total of 5081 persons in 3517 households were enumerated, and 4642 (91.4%) were examined. Thirty-six percent presented with visual acuity worse than 6/18 in the better eye. The prevalence of blindness, based on visual acuity worse than 6/60 in both eyes, was 6.0% (95% confidence interval [CI]: 5.1% to 6.9%) with presenting vision, and 2.5% (95% CI: 1.8% to 3.1%) with best correction. Blindness with presenting visual acuity was associated with older age and illiteracy. Cataract was the principal cause of blindness in one or both eyes in 69.4% of those presenting blind, and uncorrected aphakia and other refractive error affected 35.6% in at least one eye. The prevalence of cataract surgery was 14.7% (95% CI: 13.0% to 16.4%); low surgical coverage among the cataract blind was associated with illiteracy.
Conclusions: It appears that much has been done in the prevention of blindness in Sivaganga. Nevertheless, blindness remains an important public health problem, mainly because of cataract and refractive error. Prevention of blindness programs in the area should target these two causes, with special emphasis on the elderly and the illiterate.