Rear view mirror plus sunglasses question.

Factual Questions
1

When I look through my rear view mirror and I am wearing sunglasses the back window on my car appears to have a crosshatched pattern to it. Why is that?

I tried doing a search on it believing I am not original enough to come up with a new question but I was unable to find anyting. That probably stems from my incompetitence dealing with searches though.

TV

2

I would venture to say the sunglasses you are using are polorized? When you look at glass that is heat tempered through polorized lenses you will see a hatch pattern. You can sometimes see this affect on glass store front doors as well.