Hello Rich
You can't, but to protect the screen so that you can clean it regularly with no damage to the actual screen itself fit a screen protector, they are very tough. They also protect the screen from scratches, I put my Iphone in my pocket with my van keys by mistake, the screen protector had two deep scratches in it , the screen was untouched, a scratched screen also reduces the resale value of any of these devices a lot more than the cost of a screen protector.
Paul.