I don't have much to say about EK Eksessories' Cat Crap Anti-Fog Lens Cleaner other than it works and it works well.
I was having frequent problems with my clear Tifosi glasses fogging up during night bike rides. The good folks at REI suggested that I try Cat Crap to both clean the lenses and to prevent future problems with fogging. I bought the product and applied it to my glasses. Fogging problems: solved.