The power for a contact lens can be calculated based on data measured at refraction.



(1) required lens power measured during refraction testing in diopters

(2) back vertex distance (BVD) in meters (distance between the lens and the cornea)


required power for contact lens in diopters =

= (measured power in diopters) / (1 – ((BVD in meters) * (measured power in diopters)))


To read more or access our algorithms and calculators, please log in or register.