Just spray-on for instant fog-free lenses Anti Fog Spray for Eyeglass, Sunglasses, Goggles, Masks, Long Lasting Defogger For Glasses, Goggles, Ski Masks Mirrors and Windows. For best results make sure your surface is clean before using our anti-fog spray. Then spray it on and leave it for at least 5 minutes without touching the surface. You may rub it in but there needs to be a thin coating of the spray on the surface for it to work properly.