<prompt> In a population of 5000 people, 500 are already myopic on January 1, 2011, number of new myopic cases till December 31, 2011 is 9. Calculate incidence:1.802520  <response>: Incidence Number of New cases x1000 Total population under risk Incidence 905000-500X1000 904500X10002 Ref: Park 22nd ed p-58. 