How to prevent your glasses from fogging up when wearing a mask
Wash your hands with soap and water (for at least 20 seconds)
Wet your glasses then lather some soap on the lenses--be gentle but thorough.
Rinse your glasses under warm water (don’t leave any soap suds on your lenses).
Gently dry your glasses with a clean towel or lens cloth (avoid using a towel that may scratch your lenses).