I see there's an old thread on this subject, but since it's inactive, decided to start a new one (hope that's not a violation of any protocol here).
Anyway, I detest the concept of adding prism for cosmetic reasons unless that's what the patient wants. I think ANSI was wrong to allow the practice, as prism is should be a prescription item, to be prescribed by the doctor, not inserted at the whim of some nameless lens designer nerd somewhere in the world.
That aside, my main complaint is that it seems to have become an automatic add on by surfacing laboratories. This is sick. It should be an option to be chosen, not one that needs to be over-ridden on every single order by the ordering individual. Worse, labs seem to be unable or unwilling to make it an opt-in or opt out choice at all.
My worst case scenario was a guy who came in with +6 O.U. progressive Rx. The moment he put them on he exclaimed "not again!" and threw them on the counter. On lensometry check, they were spot on the Rx as ordered, except for 6^ base down O.U. The amount of prism distortion was breathtaking.
He had had the same exact experience at another provider, more than once. That got my attention.
Since then, I have made it a habit of specifying "NO THINNING PRISM, NO EQUITHIN" in the special instructions area of all digitally surfaced lenses. What a royal pain. I suspect a lot of "non adapts" are happening around the world because of this "feature".
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