https://www.mobileread.com/forums/sho...95&postcount=5
Did you read the thread a few posts down titled 'Is this normal on the Glo'? There's a photo of the screen as it's lit up right there - I haven't had any evenness issues myself, although there are a few people reporting bright spots, at least for people who bought it in Eastern Canada and one or two in the U.K.
I'm wondering how many of those are actual defects, versus people seeing the shadows at the very bottom and thinking 'OMG! I've got a bright spot!'. No complaints about discoloration in the forums about the Glo, though.