Originally Posted by
rickair7777
Plastic ones? Probably not unless it's impregnated with specific compounds to do that. I don't know for sure, but suspect they are made to be translucent to visible light, not opaque to UV.
Glass actually blocks UV much better than typical plastic, acrylic, etc. You have to wear sunblock to avoid getting burned in light GA aircraft for that reason...
I could be wrong about the boeing shades, would like to know if I am.
Glass blocks UVB -- hence why no one ever gets sun burned in cars or airplanes. (B for burn) It does nothing for UVA (aging and cancer)
Plastic does nothing.
"However, Kinder Fluff sunshades are specifically designed and certified to block a very high percentage of UV rays, claiming to block over 99% of UVA and UVB rays (e.g., 99.87% UVB, 99.02% UVA), offering significant UPF 50+ protection." (-- AI)
And if you think you only have to worry about direct sunlight, you are wrong. Significant back-scatter comes from clouds.
So, use the naked mole rat technique. Make your cockpit a cave with Kinders.
And lather on the sunscreen if you want to take the epidemic of skin cancer amongst pilots seriously.