Just a few days ago, it was more or less discovered that the artifacts were caused by backfacing polys in the glass-material. Try deleting the backfacing part of the glass with the Grouping tool. However it seems it is also related to the proximity of other things to the glass, as in how close they are to the cheeks. The lexan-material looks cool btw, eventhough the refraction is missing.

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You just can't put the words "Poserites" and "happy" in the same sentence - didn't you know that? LaurieA
  Using Poser since 2002. Currently at Version 11.1 - Win 10.