Gregory's ServerA *much* abbreviated quick answer: Any ray of light has a "polarization" which is the direction the electric part of the wave wiggles. Vertical, horizontal, or in some weirder arrangement. Most sources emit an "unpolarized" blend of all directions.
A polarizer blocks light which is not aligned with it. Polarized sunglasses are aligned vertically (iirc) because the reflections people most want to block are horizontally-polarized.
LCD monitors emit "vertical" polarized light. Turn it sideways and suddenly that's horizontal, which the sunglasses block.
I'll come back to add details!
@squeakyears @sandofsky oh oh oh .. cool I get it . I noticed what I thought were weird effects with some of my sunglasses when looking at certain cars back windows… like the reflection was all “line-y”. Ah so what was seeing was the polarization cutting out some of the reflection. It’s the kind of thing where you put your glasses up and down seeing the difference but wondering about while you are in traffic but then forget to look it up later.. thank you!!!!!