I clicked on this article because I mounted a SightMark red dot on my Ruger Mark 111 backwards two weeks ago. I had never used a red dot before and didn’t know much about them. I was very frustrated until I looked at pictures on the internet which suggested mine was on backwards. Voila! Of course I never had pictures taken with me trying to sight it with it mounted backwards.
Well, I can actually see the reticle, so I have to assume I installed it correctly. Looking forward to sighting it in.