Bought my iPad Mini Retina less than a month ago.. Have it in a case and take good care of it.. I noticed over the past week, these weird dots (that look gray when the display is on) on the screen. When the screen is off, these marks are still visible, so I know it isn't dead pixels. It started off as one tiny mark and has increased over the past week to well over a dozen spots no bigger than the tip of a pencil.. Any ideas as to what this could be? 
