Anyone who doesn't wear glasses would never understand the struggle to keep them from fogging up. I use to obssess over the anti-fog cloths but on a stormy day, they never worked. After a white out day where I could barely see my way down, I kept thinking why no one had never invented a goggle with a fan. Bottom line - these goggles are awesome! When the vision starts getting a little foggy just hit the switch and in about a minute it's gone! Flipping the switch was pretty easy with gloves. The battery life is great - I accidentally left the fan on overnight and it still worked all day the next day. One minus is that if you have wider frames, these goggles might not fit over too well (they are not as wide as the Scott Storm OTG). I had to switch to my slightly narrower back up pair to make it work but still well worth it. I bought these with the sensor mirror and love the lenses - excellent vision in all conditions.