5 The Multi Design concept and the "boucle dioptrique"

In the middle of the eighties Essilor decided to develop a new Varilux generation. It was also a new generation of R&D and Marketing people who prepared the ground for a renewal of the Varilux brand.

Prix “high-tech” of the French Magazine “Figaro” for the Multi- Design concept Gerard Obrecht (left), Maurice Dufour (third from left) , Werner Köppen(right)

The key research people for this project were Jean Louis Mercier (Director of Research) , Christian Miège, Gérard Obrecht, Claude Pedrono and Dominique Meslin. On the Marketing side the responsible Product Manager was Werner Köppen who had left Rodenstock for Essilor. Starting from the observation that for the low adds the specialty progressive Alpha for emmetropic presbyopes was more appreciated by the wearer than Varilux 2, the idea of the Multi- Design progressive was born. Each add, so each age class of presbyopes should have its own characteristic and optimum design according to the evolving needs and constraints of the presbyope with age. Up to this time the designs for the different addition powers were homothetic, i.e. their contour plots, if divided by the corresponding addition power, were identical. Essilor launched its first Multi- Design progressive Essilor VMD in 1988.

In the USA the brand name of the new lens was Varilux Infinity and in spring 1988 the Multi- Design concept was presented in two big meetings organized by Varilux Corp. in San Francisco and San Antonio [13].

Varilux Multi- Design: Different designs for different add powers

One of the challenges for the new R&D team was to create physiological analysis techniques/ tests as well as powerful and flexible calculation tools which allowed to improve systematically and continuously the performance of the progressive lens.

The Design Loop (boucle dioptrique)

In 1989 Jean-Pierre Chauveau joined the Essilor Research  team and was in charge of the Dioptric Group which conceived a new method, the Design Loop ("boucle dioptrique"). Starting from a first model of physiological requirements the research people calculated the design, which after the realization of the first prototypes was assessed by the wearer in extensive wearer tests, their feedback taken into account in somewhat modified specifications and a second improved design, tested again and so on. So this iterative process was a guarantee that the design was an optimum solution for the visual needs of the wearer. Varilux Comfort was the first Essilor progressive lens which was developed following the "boucle dioptrique" process [14] .

From left: Jean-Louis Mercier, Patrick Bertrand and Werner Köppen (1993)