10. Varilux Multi Design, the first step to a personalized design

Following the invention of Varilux, Essilor tested and launched a series of new designs. One major conclusion from the ample wearer feedback was, that there is no single specific design, which is optimum for all add powers. Maurice Dufour, a close collaborator of Bernard Maitenaz in the Varilux development, was the inventor of the patent US 4 838 674, Werner Köppen developed the Multi-Design concept. The power and astigmatism plots for the different addition powers of Mono-Design surfaces are homothetic. The patent describes how the variation of certain parameters d1, d2, ΔC allow to optimize the design characteristics per add power (vertical optical modulation). The Multi-Designs for the adds 1 and 3 of a model surface are calculated and discussed. After the Essilor VMD (Varilux Infinity) introduction the development of other Multi-Design lenses using different segmentation criteria, as for example the type of ametropia, prepared the way to the personalized progressive lens manufactured by CNC machines.

Contents

10.1 The Mono-Design lenses
10.2 The Multi-Design Patent
10.3 Calculating a Multi-Design model surface
10.4 Vertical Optical Modulation
10.5 Analysis of designs and calculations

> 10. Varilux Multi Design, the first step to a personalized design