Trieye sunglasses with built in mirror
 

I saw these featured in a GCN video.

https://trieye.com/

Has anyone tried them?

Any thoughts on the practicality of a built in mirror?

No experience.

Since I don't run mirrors on my bikes, generally - this looks better than what I have seen before.
Price, assuming quality distortion-free lens, is OK.

Back in the day you could buy tiny mirrors to stick inside your glasses. I had some and they worked very well. The trick was getting them stuck on there just right. I assume these would work just as well.

I watched the video without sound. It was superb! Got a kick out of it for some reason. The ol' stick a mirror to the lens routine has been around a long time.