I have polished headlights that have done that and got them back and made them better. Looking at them is a lot different than looking through them though.
You can curve Lexan polycarbonate as well as Acrylic. If nothing ever contacted the window to break it, tempered glass would still be my 1st choice. If you get tired of replacing them, I'd suggest lexan. I'm "frugal" so I have some equipment with Acrylic too.