NEED HELP: Screen Burn In

Hello all,

My Lumia 1520 is now suffering from screen burn; my lockscreen was apparently on too long and the lockscreen image can be screen on the phone at all times. In the bottom left hand portion of the screen, 3 blue blotches are noticeable when the screen is black underneath. I need help fixing this, so is there any apps to refresh the pixels or do I just have to wait? And if not, is the burn in permanenent?