HerrGruyere,
I saw that if I looked at one spot. As soon as I moved my eyes I would see what I can only describe as warped, rainbow ringed areas in my peripheral vision that would take a second or two to go away. This gives me an idea, is there any chance we could get any of you folks on here that wear polarized lenses at work to do a quick check in your airplane with the windshied heat off, then on and see if you notice any difference? Maybe in sunny conditions... then again when you get a chance to try it with an overcast. If we paired that with the type of glasses, and aircraft maybe we could narrow down some brands to potentially avoid, or look for depending on airplane types.
It could have a lot to do with each individual's eyes ( mine are extremely light sensitive ), and it could be something more pronounced under different lighting conditions, etc...