The finished lens is presented to the operator. The Kappa displays a "stress map" on its screen, showing green (perfect) or red (tight spots). Adjustments are made digitally – no need to reblock the lens.
The short answer:
As rimless (3-piece) frames became more popular, labs needed edgers that could do more than just cut an outline. The Essilor Kappa comes equipped with high-precision drilling capabilities. essilor kappa edger