McLeod Optical discovered that the shape of a frame tracing did not stay the same when the demo lens was removed from the tracer. “The frames would lose their shape when demos were removed,” said Scott MacLeod, president of the Warwick, Rhode Island-based lab. “The b measurement would become smaller and the a measurement would increase. This would affect the first time fit at edging and the cosmetics of the job would be off, causing customer complaints.”





To avoid this problem, the lab uses a DVI program called Pattern Merge. “Basically we trace the frame for the circumference and then trace the demo lens for the shape,” MacLeod explained. “The program also allows for the two to merge, and the result is what the ECP was looking at.”

He continued, “The trace operator is trained to notice if the frame collapses and then traces accordingly. The interface is at the trace station and the operator is responsible for the quality of the shape. The axis of the pattern can be adjusted too.”