Originally Posted by
Ogsarg
I use a take-a-look mirror on my road bike. It attaches to your glasses and is very effective. I don't ride without it...or at least not on the road.
https://takealookactive.com/
Several up-votes for the take a look mirror. I'm adding one more for it. The downside is that for me I need to clip it onto a visor on the helmet. Many helmets don't have a visor so that could be an issue. Aside from that it takes about a ride or 2 to get used to it. I found that my eyes wanted to focus past it the first few times if that makes sense. After that it's great and I don't leave home without it.