Disclaimer- Essilor employee.
I really think you've hit on the real issue (i.e., increased vertex distance). Also, a +1 to center pupil placement. I know some PALs work better with a modified fit, but Varilux lenses really perform their best at pupil center. Not saying Varilux Physio W3+ is a perfect solution for every patient- and it may not be the best solution for this particular patient at the end of the day- but there are a lot of hyperopes happily wearing that design (as stated, each person's visual system is unique- which is why it's a good thing we have 100s of PALs to choose from). Hoping you find a good solution for this patient- regardless of which design provides the answer.
Not to get too far off the topic of the original post, but regarding contour plots I really REALLY wish you could determine how a lens will perform based on it's plot (because it would save me a TON of money in wearer studies). Unfortunately, experience shows that contour plots are virtually
useless in telling me how a PAL will perform in real life (probably because they only contain information on cylinder and sphere levels without showing the axis of the cyl or the balance of corresponding points).
That's easy to say, but let me give some examples. First, a couple of contour plots Darryl gave me years ago. The lens on the left has an obviously narrower intermediate and a LOT more unwanted astigmatism than the lens on the right. So, according to the plots, the lens on the right should be far superior...
The lens on the left is SOLA VIP (which- for its age- is still a decent PAL, I have a pair myself). The lens on the right is SOLA XL, which was originally supposed to replace VIP and later was positioned as a complimentary lens to VIP. VIP has always been FAR more popular and quite a few of them are still sold today.
Using a more modern example, here are two Plano +2.00 plots I made a few years ago prior to a wearer study (the lens on the right is a non-Varilux Essilor design and the lens on the left is a competitive design). When I made the plots, I thought
"We are going to absolutely KILL this lens for distance width!" In real life, however, there was no statistically significant difference in perceived width (in fact, the competitor lens on the left was preferred by one more person in an n=33 study than the lens on the right for distance width, which still left us with a p=1.000, or "no difference"). In fact, there was only ONE statistically significant difference in the perceived performance of these two lenses (the lens on the right was significantly better for transitioning between distance, near, and intermediate).
Point being, although it seems logical you could predict performance from contour plots, you really can't (at least I can't, and I can create some pretty cool plots :^). I've seen this in study after study. Here's why (at least IMO)... Spherical width and max level of astigmatism are NOT the most crucial aspects of a PALs design- but that's all a contour plot will show you. It makes sense if you think about it, a FT28 has 26mm or so of spherical width and virtually no unwanted astigmatism- yet most studies have shown people prefer the functional vision provided by PALs (even though a PAL has
significantly less spherical width).
Progression rate, binocular balance, and prismatic effects all have a profound effect on wearer perception, and none of them are shown by a contour plot. Here's a plot of binocular balance comparing the binocular fields of two generations of Varilux progressive designs (think 14-20 years ago, one of the products isn't even available anymore). The lens on the right provides far superior binocular balance- which is why patients were much more comfortable in this lens (IF it was fit accurately). However, these two designs look very similar on a contour plot (in fact, I remember going back and forth with one educator who plotted the lenses and claimed there was "no difference" between the two). These plots were included in the original education on the new design, but were later abandoned because it was too difficult for most opticians to understand their significance.
Oh, and yes we still sell DEFINITY (currently DEFINITY 3 :^).
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