The refractive index of ophthalmic lens is calculated from back vertex power, surface power and central thickness as measured using a focimeter, lens masure and thickness gauge. The value of the refractive indices were calculated to be 1.502±0.011(me...
The refractive index of ophthalmic lens is calculated from back vertex power, surface power and central thickness as measured using a focimeter, lens masure and thickness gauge. The value of the refractive indices were calculated to be 1.502±0.011(mean±SD) for CR-39 plastic lens, 1.522±0.022 for crown glass lens, 1.613±0.017 for medium-index glass tens and 1.701±0.011 for high-index glass lens.