Optimization of the optical performance of variable-power and astigmatism Alvarez lenses.

We first explore the operating principle and optical performances of dioptric-power and astigmatism-variation lens doublets based on the L. W. Alvarez design. These fall within the scope of two ophthalmic applications: ophthalmic glasses for the correction of presbyopia, taking into account any type of ametropia, and spherocylindrical refractors. Second, we present a multiconfiguration optimization method leading to improved optical performances of such doublets over a wide field of view. We then investigate the particular distribution of the curvature on the complex surfaces of the two lenses after optimization.