APPLE INSIDER
Future head-mounted displays, such as “Apple Glass” may automatically remove dust obstructing the wearer’s view.
If you wear glasses, you also have a cloth you use to repeatedly clean them, and you may still need to wipe over “Apple Glass.” However, a newly-revealed patent application shows that Apple is looking to keep the inside of the device clean by itself.”Particle Control for Head-Mountable Device,” discusses how a device could itself remove dust or other debris, from what Apple refers to as “optical modules.”
Source: APPLE INSIDER