UPDATE: Last week I ordered another Take a Look Mirror and today I got to try it on my road bike. I put them on my glasses and LOVED THEM. I can really see behind me which was great for cars and looking at my buddies that were behind me (and a sneaky one sucking on my wheel). I will have to try to mount them to my glasses on my mtn bike commuter. I tried to mount them last night but no go because of the shape of the glasses but I think tape will work.