polarized sun glasses

[larco]

I have always worn non-polarized sunglasses as I was told polarized glasses limit the view ability of screens while flying.
I need to get replacement glasses very soon like next week, and the place (Costco) only sells polarized sunglasses now. So, my question is: Is there anyone out there with the advanced EFIS displays and Garmin avionics wearing polarized sunglasses without a problem or complaint??
A friend here has a 2500 in his 6 and has no problem with the polarized glasses he wears which is a surprise to me, my concern actually surprised him as well so I’m reaching out.
knowing that some screens have changed but also wanting to have the best glasses for anti glare, I’m throwing this out on the forum hoping get some good feed back.

Thanks, Larry

[Shawn McGinnis]

Sunglasses should be horizontally polarized according to my readings and tests. TFT LCD monitors are polarized on at 45° to improve viewing angle of the vertical and horizontal axis. Malus' law reads that the intensity of light after a filter (your sunglasses) = the origination intensity * cos^2(θ).

Long story short wearing sunglasses with your head eyes parallel to the screen you should see half the brightness compared to non-polarized lenses. This is almost true but you have imperfections that cause the brightness to be a bit higher than half. If you were to rotate your head 45° CW the screen will darken significantly (a perfect systems would be completely dark). Rotate to 45° CCW and the full brightness would return.

AF-2500's get around this half brightness some because they are transflective and allow light to return from the panel negating some of the polarization effect.

[larco]

Thanks for the reply Shawn. We here locally have spent some time this last week messing with polarized glasses and have found exactly what you state to happen. Now off to a different source for glasses. Larry