system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Which of the following statement is true -
assistant
The correct answer is  Ans. is 'b' i.e., Cohort study involves large number of subjects* Prevalence of blindness in India: 700 per 1 lakh population (0.7%) if cut of criteria is < 3/60 (WHO criteria); or 1100 per lakh population (1.1%) if cut of criteria is < 6/60 (NPCB criteria).