A process, phoropter, and an optometry system, the process being for correction of the shift of the optical power of an active lens in a phoropter due to a temperature change over time, the active lens including a container filled with a liquid and having a deformable curvature membrane under the action of an actuator controlled by an optical power control command, the shift being that the active lens provides an actual optical power that is different from the expected optical power corresponding to the optical power control command. A temperature sensor is arranged in and/or on the phoropter to measure the temperature in the phoropter.