<prompt> If blindness is surveyed using schools as compared to population surveys, then estimation of prevalence of blindness will have ?OverestimationUnderestimationRemains sameNone of them is used for evaluation  <response>: Blindness situation in IndiaEstimated prevalence of blindness in India total : 11.2 per 1000 population.Estimated prevalence of blindness in India 0-14 years : 0.1 per 1000 population.Estimated prevalence of blindness in India 15-49 years : 0.6 per 1000 population.Estimated prevalence of blindness in India 50 years : 77.3 per 1000 population.So if schools are used where only refractive errors generally constitute blindness that too very few are actually blind i.e. 6 60 As compared to population where age-related cataract constitute as major cause of blindness, it would lead to underestimation of prevalence of blindness in the country. 