The Oculus Rift DK2 lenses scratch far to easy. Here's an easy fix. Screen protector used : 6x Savvies SU75 UltraClear Screen Protector for Watches (circular, Diameter: 40mm)
Not covered in the video : Grease stains/Fingerprint removal.
if you have grease stains/fingerprints before you apply the screen protectors, take a CLEAN and good quality microfibre, NEVER reuse it, fold it four times and wet the microfibre with some metanol. (WARNING:USE A SOLVENT COMPATIBLE WITH THE SUBSTRATE OF THE LENS) and with just the pressure made by the fold of the microfibre slowly swipe the lens to its periphery.