We all face this issue, dust and lint on the little screen above the mirror that displays our af points and all that, but I can't for the life of me think of what it's actually called. I've become very frustrated with not being able to get it clean however, as some pieces of whatever seem very committed to staying on there. I currently use a combo of my hand blower, canned air, and a microfiber cloth and brush, but no matter what, it stays put (it does move, so it's not a scratch).