Monocular vision can really work extremely well for some people, especially if it's achieved without lenses. When I was a kid, I was very neasighted in one eye, and only moderately nearsighted in the other. The better eye was, of course , dominant. When farsightedness set in, the bad eye became the reading and close up eye. It sees clear as a bell out to about two feet. My good eye became gradually better, as slightly nearsighted eyes often do as you age. My dominant right eye is now 20/20. My neadsighted eye is 20/300, but I can see perfectly with it down to only a few inches, read, etc., with no effort. The brain automatically switches from one eye to the other, according to the task. I can actually feel the shift happen, if I suddenly look up from a book and look at something a distance away.
When I was young, my very different levels of nearsightedness was a problem, because one thick lens and one thin lens made glasses crooked and unbalanced. The happy result of this condition, though, is that now, in my early 60s, I don't need glasses or contacts at all. One eye does distance, the other does closeups, and the brain fills in the blanks in such a way that there are no blind spots; you efffectively seem to see perfectly with both eyes, close up or at a distance.
Some nearsighted people have this monocular vision created artificially, by having laser surgery in only one eye. I have it naturally, and I thank my lucky stars when I see people struggling to see computers, focus cameras, etc.
On another topic, a colonoscopy is easy, totally pain-free. I have one every three years. It's no big deal, and lots of stubborn, uninformed people doom themselves to an early painful death that could easily have been avoided with a simple exam.