Originally Posted by
2manybikes
this is the best. It mounts on glasses, helmet, or or visor. It's the strongest one I have seen by far. I have mine on my glasses, it is more stable that way. I takes a few days to get used to all of these kinds of mirrors. I know a few others who have been using them for a decade too.
http://www.amazon.com/Bike-Peddler-C.../dp/B001VTQNVO
That's my favorite too. The thing that I like most about it is that it allows me to direct it's field-of-view by moving my head.