My MacBook Pro (mid 2012) has display burn-in near the centre of the screen that I just can't seem to get rid of. I've tried all of those burn-in fix videos, and I've even left a white screensaver running for over 24 hours straight. My problem seems to be different from most I've encountered on my quest to fix this, as my burn-in is only noticeable on black screens and other very dark images. A plain white background or pretty much any other bright colour for that matter shows absolutely no burn-in. I've included images of my issue: one with noticeable burn-in, the other without. This has left me quite worried, because most people claim their burn-in resolves after running a few fixes. Mine has not, which leads me to wonder if this is something other than burn-in, or if my problem is just too far gone to fix. All assistance will be greatly appreciated.