I think the real question is not staring at pictures and doing photo manipulation. The real question is, how is it for you and your eyes when you actually read a book on the device. Nothing else really matters.
Do you notice anything while actually reading. Not staring at empty pages, or taking pictures. If you can't read comfortably, I think you'll have the answers. Those screens are so different from one another and each of our eyes are different. I don't see any gradient on my current O2, but I did see some on my first one. I got a replacement for a different reason though, I had a stuck "pixel". I would have kept the first one otherwise, although initially I could see the darker side. I don't see it at all on my replacement though. So I know what it looks like, but tolerance will be different for each person. I think a certain level is expected just based on how the lighting technology is done.
|