Fogging is caused by a “phase change” of water vapour to liquid. This occurs almost exclusively when warmer air meets a cooler surface. So if you use your LiP Watershades in a cold water environment, read on…this advice is for you!
For watersports sunglasses, the main cause of fogging is when warm air from your body or your breath comes into contact with lenses that have been cooled down (either by the air temperature or by the water temperature). The water vapour in the warmer air condenses into tiny droplets that cling to both the inside and outside of the lenses.