A_Person

I recently had my cracked, iPhone 6 screen replaced by a 3rd party repairer. Coincidentally, I also bought a pair of snazzy polarized sunglasses for an upcoming boating trip.

The first time that I turned the phone on, while wearing the glasses, on the boat, the screen stayed black! Much cursing and swearing ensued ("frickin' repair only lasted 3 days!!" etc.) Of course I soon realized that the screen was strongly polarized. It was fine when held horizontally, but completely black when vertical.

I checked various other LCD screens on the boat, eg. autopilot controllers, chart plotters, my friends' phones, and so on, and none of those were polarized. So my question is, is it common for LCD screens to differ in that property? Does it suggest that the 3rd party screen is lower-than-normal quality?

(ps. I have poor internet connectivity at present, and might not see replies for a day or so.)