I bought a ProVision SunFog Visor Insert from MCAS ($27.95) - hoping it'll stop the fogging and remove the need to switch my normal glasses for sunnies half way through a trip.

See the pic below for what it looks like when attached. The insert is the thing with the black rim. It's a clear insert, but I think the flash has made it look darker.The black rim is noticable when riding, but doesn't cause any vision problems - which is something I was concerned about when I pulled it out of its packaging.

As far is its anti-fog capabilities are concerned it's excellent. I know it's working cos I can breathe out normally at 6:30am and it won't fog up. I can see the visor around the insert fog up, but the insert is nice and clear - I just need something to make my glasses anti-fog now ;)

It's photo-sensitive capabilities are ok, but I don't think they remove the need for sunnies. Early morning sun doesn't appear to be strong enough to trigger it - but it's strong enough that I wish it did. During the day it's reasonable. It changes in a few seconds, going a reasonably dark shade of dark purple, and when you hit shade clears pretty quickly. However, it needs direct sunlight to trigger it. Sun from the side doesn't affect it (at least not enough), and sun reflecting off cars, buildings, or the road doesn't appear to affect it much either.

So, to summarise, it's anti-fog capabilities are awesome and well worth the money. It's photo-sensitive capabilities are useful enough if you've forgotten, or can't be bothered, with sunnies for a bit, but for me I'll still be using my sunnies too.

ty