The Result Of 28 Years Of Direct Sun Exposure [Pic. This 69-year-old man was a truck driver for 28 years. He was hit by direct sunlight on the left side of his face.
Saturday, June 2, 2012 4:18:00 PM
Maybe it happened on those days when it was hot and he had the side window open.
The side window could have been up, and he'd still probably have got enough UVA exposure through it to cause deep wrinkles like those above. The windshield of cars, being laminated, blocks all UV, whereas the side windows generally only block UVB (which causes sun burn and melanomas), but allow a fair percentage of UVA (which causes wrinkles) through.
Saturday, June 2, 2012 2:11:40 PM
>Car windows, while blocking UVB, offer you little protection against UVA.<
I'll offer you a quote from Richard Feynman, the Nobel Prize winning physicist, who used a truck windshield to protect himself from the harmful effects of UV radiation coming from the first atomic bomb test:
"I got behind a truck windshield, because the ultraviolet can`t go through glass, so that would be safe, and so I could see the damn thing."
"In the majority of modern cars, the windshield is built of laminated glass that blocks all of UVB and the vast majority of UVA."
When you say glass lets a high percentage of UVA through, you mean ordinary glass, not the laminated glass used in car windshields. Only light coming in the side window you`re actually sitting at will be harmful.