Prevalance of cataract at one point of time can be determined by:
Ans is 'b' i.e. Cross-sectional study RepeatCross-sectional or Prevalence study - in cross-sectional studies, we 'survey' several individuals at one point in time and collect information on health status, health-related behaviour, and other exposure factors. In this way we can estimate the burden of disease in a group of individuals and try to estimate whether a particular exposure is linked to a disease or health outcome.
Longitudinal study
Cross-sectional study
Surveillance
Cohort study
Analytical Epidemiology