PD and the rest is automatic. Percepta uses several advanced optical principals, like Zone Congruence and Eyepath Alignment, to compensate for the changes in the convergence of the eyes, and to ensure perfect alignment of the visual axes through the various zones of the lenses. Therefore, Percepta has varied insets and corridor lengths based on magnification effects and Zone Congruence requirements. However, the near zone measurement circle has been conveniently placed in one location to ensure easy near zone verification. It isn t possible to describe Percepta in these simple terms.
Most people think that hard designs have wide viewing zones, and soft designs have narrow zones.
But SOLA has found that controlling the rate of change in power, alone, is not sufficient to achieve the maximum performance. A progressive lens must also provide the proper amount of visual field at each distance for every patient regardless of prescription. With Percepta, SOLA carefully controlled the amount of the lens surface dedicated to each visual field, to give the best performance under a wide range of conditions. During our clinical trials, many of the participants were satisfied progressive lens wearers who had been wearing both our earlier lens designs and competitive lens designs. The great majority of these patients were successfully converted to the Percepta progressive lens design.