Shortly after purchase I used the goggles extensively on a trip to British Columbia. They functioned flawlessly. I turned the fan on whenever there was a hint of fogging and it cleared within less than 30 seconds. The lens functioned well in light conditions varying from bright sunlight to heavy shade - although it was better in moderately bright ocnditions. The only minor drawback is that the strap requires a lot of adjustment to fit on a helmet. Despite this I would recommend the goggles for anyone who wears glasses and has a fogging problem - prior to using these I always had a problem with fogging and no-fog cloths, vents, etc. did not fix it. This is the only product
that has worked for this.