This snow goggles is perfect for OTG, GOOD for sunny day only. does not fog at all. If you wear this in cloudy day, the slope may seem all the same to you, the bumps are invisible to you. Do not wear this in cloudy day. The ability of preventing fogging is awesome, I snowboard all day for 8 hours. It does not fog at all. However, the size of this goggle is a little too big for me. I am 5'7'' tall Asian. Only a small part of my nose is exposed, it does not affect my breathing, just do not have a super good looking.