Uilleann

Their are many inconsistencies in the DiSanto article.

1. He uses the threshold for TCA as 0.25D when Mo Jalie clearly outlines it as problematic at 0.10D, even if we were to use the ANSI standard for power error of 0.13D as a threshold it would be more appropriate then more than doubling the threshold to prove his point.

2. SV lenses will have very little complaint from ABBE, but PALs and Multifocals require off axis gaze to utilize reading segments. This simple fact makes ABBE more important to consider in PAL and Multifocals than SV.

3. He speaks of molded lenses being produced better and then refers to constringence as an aberration which has nothing to do with ABBE.

4. Aspherics allow the designer to mimic best form spherical lenses to suggest that aspherics offer cleaner optics (except in certain high plus circumstances) is not the truth and should not be taught as such. In certain cases where the power goes above +8.00 their is no best form spherical lens so in these cases an aspheric is necessary, but to suggest that this is the norm is poor advice.

I have books written by scholars that debunk what this article written in a magazine says so to me the book will trump the article all day, the majority of the images in the article as well comes from Essilor with the last image actually having citation to Essilor. This company is known to promote polycarbonate as their flag ship material. Keep in mind that this is an editorial piece and was not verified for accuracy. Even CE's by the ABO often times have some conflicting information presented but at least you can trust that the author will disclose any affiliation or conflict of interest.

I dont argue with anyone who uses sub and superscripts in his posts. ;)