Muc off anti fog treatment uses cutting edge moisture absorption technology with an anti mist formula to create a transparent micro thin coating so your ride is never cut short by foggy goggles our anti fog treatment lasts up to five days and if you spray on the outside of your swim goggles or sports glasses the anti mist formula will help rain bead off to make your ride that much saferand with muc off39s long lasting formula you39re goggles will be fog free for up to five days