Follow–up of cataract operations in national blindness control program is done by –: (A) Active surveillance, (B) Passive surveillance, (C) Sentinel surveillance, (D) Routine check-up
Answer is C. 25 sentinel surveillance units have been established in departments of ophthalmology and PSM in medical collages in India for assessment of -
Beneficiary profiles.
Visual outcomes based on cataract surgery records.
Follow-up of operated cases.  
Ocular morbity data.