VisionPlus India

VISION AND BEYOND Everyone seems to be using (or rather misusing) the word ‘freeform’. Pratik Bhatt, sheds some light on this topic FREEFORM : AREFERENCE GUIDE THE HISTORY The idea behind the power progression in one single lens without the dividing line seen dates back to 114 years ago! The first patent for a PAL was British Patent 15,735, Though never commercialized, it was granted to Owen Aves with a 1907 priority date. This patent included the manufacturing process and design. Unlike modern PALs, it consisted of a conical back surface and a cylindrical front with opposing axis in order to create a power progression. F irstly, let's understand the term freeform. To explain in a non-technical way, freeform technology uses a computer assisted generator. It generates any complex designs directly with the semi-finished base between a hundredth of a dioptre. Instead of using the traditional method of moving the knife around a single point, this generator is capable of moving around the surface of a spinning lens, incising and shaping the lens where necessary . 46 VISION PLUS INDIA EDITION