20/20

Lenses

September 2017 Education

A Dispenser’s Guide to Compensation –
Part 2

In Part 1, we discussed Position of Wear measurements and how they affect compensated power. Now you’ll see why. Are all these measurements necessary? The answer is yes and no. To create compensated lenses, we must use values for one or more of the key POWs.
May 2017 Lenses

Discussion points for ANSI Z80.1 – Focimetry Issues Part One

In preparation for the 2020 revision to ANSI Z80.1, the committee has been reviewing topics relevant to the revision and seeking input. One area identified is Focimetry, where many questions are commonly asked. At the March 2017 ANSI Meeting (and subsequent Vision Council Lens Technical committee), a document I drafted was reviewed for accuracy of content. The following Focimetry related topics and responses were reviewed by both committees, and represent a consensus of opinion on the topics raised. Given the length of this document, it has been broken up into two parts.