Virtually any LCD screen will produce polarized light. This is the core working principle of those screens. So if you use a polarized filter (sunglasses for exa

Virtually any LCD screen will produce polarized light. This is the core working principle of those screens. So if you use a polarized filter (sunglasses for example) it will completly block the image coming from the screen. You can see the effect here: https://www.reddit.com/r/mildlyinteresting/comments/crvpil/the_way_you_can_see_my_laptop_screens_polarizing/ https://www.reddit.com/r/mildlyinteresting/comments/crvpil/t... I believe this will not work with OLED screens though, but I do not have one to test this.