There’s an ALPA newsletter covering this but I can’t find it.
Here’s a study done 10 years ago: http://www.dtic.mil/dtic/tr/fulltext/u2/a471609.pdf

Boeing windshield construction:http://www.ppgaerospace.com/getmedia....aspx?ext=.pdf

Notice there is no plastic which absorbs more UV..

The FDA regulates sunscreen in such a conservative way that sunscreens available in the US generally suck. I buy Japanese sunscreen that available on Amazon. Their stuff is way better than anything we can get here.