HJC’s anti-fog treated shields are anti-fog coated both on the inside and hard coated outside. When first using the anti-fog, you must activate the anti-fog by breathing directly on to the shields interior surface. The shield will partially fog, once the fog clears it is activated. You will notice if you breathe on the shields again, it remains fog free. All anti-fog coatings are a chemical treatment and will wear off in time.