I have had a bike for ten years or so, and I never bothered to get a bike mirror. Recently, in a new location, I was gifted with an E-bike. Whoa! I figured I should be responsible, so I determined I needed a mirror (or mirrors) for the bike. I tried a mirror attached to my handlebars, but it was unsatisfactory. The distortion of distance and size of objects behind me rendered it useless. I tried a humble mirror, the TAKE A LOOK CYCLING MIRROR, a long wire with a mirror at one end, and the other end attached to my sunglasses. I got two, one for each side. Aside from how dorky these mirrors looked, they actually worked great once I got use to them. However, I found them awkward somehow. When I saw the TriEyes solution on YouTube, it immediately caught my eye. (I got one with mirrors on left and right shades. It seems to me silly to have a mirror on only one side. Hazardous traffis and impediments can come from any side.) The dorky TAKE A LOOK mirrors undorked, nice shades with mirrors hidden (mostly) discretely behind the dark lenses. It takes a similar brief awkward "getting used to it" period of a few days, as the TAKE A LOOK mirrors, and once one learns how to position them, they work GREAT! I wear glasses, and I wasn't sure these would fit. I see there are clip-on TriEye shades available, but with the mirror on only one side. I want mirrors on both sides, so I took a chance and bought the regular shades. They work find, fitting well over my seeing glasses. (However, if a clip-on version with mirrors on BOTH sides were produced, I would probably get one of those, as well.)
In short, i love this solution to biking safety. I love my TriEyes!