I don't know which type of glass my glasses have, but I know I had to pay a ton for it, because the cheaper sort can't handle my prescription without being really thick and/or heavy. But as someone that actually wears my glasses all the time and not just randomly, it's worth the extra expense.
Interesting, is the lens ultra high-index? How's refraction? As far as I'm aware, high-index, as the index becomes higher, generally will have a progressively worse Abbe number.
