Love reading threads like this- nice to know there is still a wealth of dispensing knowledge out there!
One more consideration from the design perspective (based on my own dispensing experience)... I found relatively "hard" designs work well for patients with prism, because these designs tend to have a better defined "sweet spot" which a.) creates a "locator" for the eyes and b.) allows the patient to describe any misalignment of the sweet spots (as was noted in the OP).
To be honest, the best results I achieved for patients with prism were with the ultimate in "hard" designs- blended bifocals (let the flaming begin :^). By adjusting the fitting height and inset, I could usually provide very comfortable distance and near vision without a line (and, at least in my experience, intermediate vision is always a crap shoot for these patients anyway). With a few exceptions, progressive designs challenge binocular vision anyway- and someone with prism doesn't need additional challenges (IMO). If the patient did a ton of work at the computer, I'd recommend and fit blended lenses with the intermediate entered as the distance script and half the ADD for near (even for patients without prism, this set-up works great for computer lenses).
Disclaimer- Essilor employee... If I were selecting a lens from the Varilux portfolio for the scripts mentioned in this thread, it would be either a traditional Varilux Comfort or a Varilux Comfort DRx (most likely the former) in 1.60. While I love multi-surface designs, I agree with sharpstick777 that this amount of prism might be better suited to a single surface design.
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