Third EyeEyeglass Bicycle Mirror

The frame is hard black plastic. The mirror is actually silvered glass: a REAL mirror! Not cheap mylar on plastic. The reflection quality is pretty good as long as you've wiped the smudges off. If you're not bouncing around too much you might even be able to read the license plate of the car behind you. Adjustment is simple: there are two plastic balls that allow the mirror to swivel left-right and up-down. One is right on top of the mirror. The other is on top of the clip. Several other people have mentioned in their reviews that the mirror will move a little bit if you take your glasses off, and this is true, but it's pretty easy to re-adjust it if it does slide a little bit out of focus.One thing I would recommend, is having a pair of glasses dedicated as your riding glasses (or your mirror glasses) and either super-glue or cable-tie your mirror onto the glasses "permanently" so that the mirror doesn't fall off and break when you take the glasses off. This will also prevent the mirror from jiggling and sliding around on your glasses while you ride (or whatever you do while you wear the mirror glasses).Consider yourself warned... this unit works best for glasses with THIN ear-frames. If your glasses are too thick in the part that goes over your temples where the mirror should attach, there is a chance that the mirror's clip is too rigid and you will not be able to make it fit without breaking one of the fingers off the clip. If that happens, grab a cable-tie or some super glue and permanently attach the mirror to your glasses... or grab some duct tape for an ugly but temporary attachment.

These mirrors are easy to adjust and after getting good with moving my head to look behind in different directions, they became a must use for any ride. It took a couple of hours to get used to them. I feel exposed on the road without one. Much nicer than handlebar mounted mirrors. The two downsides are: 1, the little prongs which clamp the mirror to glasses eventually break 2. Thick armed glasses won't work with these.

I like the Third Eye Eyeglass Mirror, which I attach to the brim of a visor instead of glasses when rowing. I like it because it's symmetrical (thanks to two universal ball-in-socket joints) and can be mounted equally well on the right or left side. I prefer right because, when I initially bought it, it was to make me faster on HOCR turns, where most of the buoys are to port. It's been there ever since. Speaking of which, in a race situation it saves a look every ~10 strokes. That adds up. The mirror is glass, and when I remember to clean it, the visual acuity is quite good. It has a limited field of view, or viewing angle. It's plenty for my boat and oars, but not lots beyond that. One has to be attentive to boats / hazards coming from the side. For me, the narrow field of view is a feature, not a bug, because I think a mirror with a much larger one would be distracting. But that's a matter of personal preference.Downsides. It takes time to learn and isn't natural the first few outings. It's not great in rain. This particular mirror is made of plastic and can break or wear out. I've gone through 5 or so. But if you get one, keep the label off the packaging. It provides instructions on how to return your mirror(s) for roughly half off MSRP - I did this in bulk, 3 mirrors at a time. But at $11 you may be wondering why go through the bother.I've also own the Bicycle Peddler Mirror. Pros: metal, more durable. Cons. Not symmetrical; mounts better on the left. Doesn't seem to adjust as well where I can sight down the bow deck and bow ball to the horizon with just a slight tilt of the head. Does not stay on a cap or visor as well. Easily knocked off with a glancing blow. Last time it ended in the drink off the dock. But the water was clear and I was able to retrieve it. Brrr.PS - Regarding the dork factor. Definitely. Oddly, I'd never wear one cycling. (Although, I used to race with a guy who used one, contrary to USCF rules. He'd tell the officials that he used it for commuting and he had just the one helmet. Total BS. His real purpose was to scan the field behind him for anyone who was about to jump, and then jump on their wheel. He won more than one race employing this tactic.) But the advantage I find when rowing outweighs any style concerns. Says a guy with out of control hair.

Fits easily to temple side of glasses and enables a rear view of oncoming vehicles without having to turn head. Good value and multiple adjustments to accommodate different angles.

The stem that holds the mirror is not long enough for it to be worth it. It actually gave me a headache trying to look in it because it's so close to my eye/temple.

I’ve always used this mirror when riding (maybe 30 years) It is steady for clear viewing to the rear. Fits on flat stemmed glasses. Stays firmly on the glasses which allows a steady view.

I wanted to like this mirror, as I've used the Third Eye Helmet-Mount Pro for years with good results. But this model had two shortcomings: the arm attaching the mirror is too short to allow a useful rearview perspective; and the relatively inflexible attachment fingers will not hold on reliably to my sunglasses.Update: I have now exchanged the two Third Eye glasses mount mirrors for two Helmet Mount units--thanks to Bell's Bike Shop in Phila. Great people there--thanks for your assistance!

I've broken two of the brackets that attach to my sunglasses. I leave the mirror attached to my sunglasses when I'm not using it to reduce the stress of attaching/re-attaching the mirror to the glasses. I've still broken 2 of them. Very frustrated and am looking at redesigning the bracket and 3-d printing it....