In reply
The notion of a CSR is a useful planning and monitoring tool; it is defined as the number of cataract surgeries done per million population per year. Theoretically, when the CSR equals the incidence of eyes with cataract (expressed as new eyes with operable cataract per million people per year) for a number of years, a steady state is achieved and cataract is gradually eliminated.1 Taylor's points about the effect on the CSR of the visual acuity threshold for surgery and the percentage of the population older than 50 years are critical to the concept. Our model was designed to take both into account.