This question is somewhat wrong. You don't need sunglasses for screens, you need it against the sun!!
Surprising, isn't it?
So, if you look at screens only, take the sunglasses off! If you have sunlight, try to find the protection you prefer most.
If you have to look at screens and in the sun then you have to find a compromise between best protection and least obstruction. I might have to come back to my other post where I favorize Oakley. They tell you for every lens type how much light they filter out. I might be a fearful guy so I always use black iridium (non polarized of course), which gives you roughly 95% protection from the sun. I still can see the screens, although I have to put the screens on max brightness sometimes - but hey, that's what this handy dial is there for! Other Oakleys claim to filter out between 13 to 90% of the visible light.
There are ongoing disputes about colour changing efffects. I have never seen that problem, but it might happen to colourful glasses.
hth
Dani