I must first say that I have been riding an old Peugeot road bike for 38 years, equipped with a Mirrycle rear-view mirror which has served me very well, both in monitoring traffic behind me and in keeping track of other cyclists on group rides. My new bike with modern brake hoods and internal cable routing will not support this mirror, so I was looking for alternatives and saw these glasses. I bought a pair of the clip-ons and also an Italian rear-view mirror that attaches to the left brake hood with Velcro. I was suspicious of the mirror mounting, but pleasantly surprised that I could get it secured tightly enough because the mounting plate matched the shape of the brake hood exactly, so there is no noticeable wobble. It does not provide quite as large a field of view as my old Mirrycle, but almost. The image seems a little darker, however. The TriEye glasses took a while to get the mirror adjusted just right. This might be easier to do with your bike on a training stand and other bikes parked in various positions behind it than under actual riding conditions, at least at first. The mirror is good at staying where you set it, even after putting the clip-ons into and removing them out of the case multiple times. Getting used to using it while riding does take some time. The information on their website warns that you will need to rotate your head about 15 degrees to the left in order to see what is coming up behind you, and I adjusted to that very quickly and easily. What I found more challenging was learning to tip my head up slightly to see further down in the mirror image, and to tip my head down slightly to see further up in the mirror image, but still, after half a dozen group rides, this became more natural. I have been very pleased with the brightness of the image in the mirror. I can see the expressions on my cycling companions' faces! However, for seeing things further behind me the mirror mounted on my brake hood is superior. I like the clip-ons because I can maintain the functionality of my regular trifocal glasses.