Bought some stuff called "cat crap" yesterday which seemed to work really well until I started a return journey after riding a few hours and got stuck at some lights a few times, by then my visor was really fogging up with concentric circles around all the lights all over my visor, not just at the bottom near my mouth (more distracting than before when I hadn't applied anything). IMHO it might have been better not to use the stuff and just lift the visor at lights, perhaps I used too much or not enough? Hmmm: http://www.webbikeworld.com/r2/motorcycle-helmet-visor-anti-fog Odd in that it worked really well until I'd been riding for about 2-3 hours, then the halos started. http://www.tiltedhorizons.com/2007/09/cat-crap-anti-fog-treatment.html didn't like it either. Guess I should try inserts as mentioned in this forum. A.