@prefec2 @taixzo @Unabart @sandofsky Most OLEDs use polarizers and wave plates to reduce reflections which would otherwise come from internal components. You lose brightness (~50%), but gain contrast. This is one of the reasons why the efficiency of OLEDs is lower than one might naively hope.

Here's one model: https://optics.ansys.com/hc/en-us/articles/5845197523731 (Note that the front of the display is at the bottom of the diagrams, and unfortunately the OLEDs themselves are left out.)