https://www.acplasticsinc.com/informationcenter/r/what-is-lexan
It’s the UV rays that effect Lexan and other petroleum plastics.
UV protection glass, sorta like polarized, but different could provide the protection needed.
For a difference inuv vs polarized here’s some explanation.
http://fashioneyecenter.com/polarized-sunglasses/
Think of UV as wavelength and polarization as a rotational angle of attack...sorta.
Plexiglass, which is acrylic vs petroleum based, may be a better alternative.
https://www.theclassroom.com/effects-of-the-sun-on-plexiglass-12080213.html
should have said acrylic vs polycarbonate as acrylics are still petroleum based.
sigh. ... night
Super thanks for the links & info. Pondering a building project or two in the next year or so. Very helpful. Have a great weekend.