Small white square appearing on screen
Yesterday I was looking at my iPhoto pictures and every picture had 2 small white squares appear on the screen which I tried to edit. Only to find this morning I now have one white square appearing on the Mac book pro screen. I cannot get rid of it.
Please can anyone advise me how to remove it and what is causing it?
Thanks
Carol
MacBook Pro with Retina display, iOS 7.0.4