Imagine being able to see three times better than 20/20 vision....
Uhhh... You'd need glasses to be functional.
That doesn't mean "permanent binocular vision". The term "20/20" means at 20 feet (the first 20) you can see things an average person can see at 20 feet (the second 20) away. So if your vision is 20/100, you have to stand 20 feet from something to see it as well as someone else that's 100 feet from it.
I've known two people that were classified with 20/15 vision, and I believe babe ruth was similarly gifted. (if the pitcher didn't hide the ball in his glove, he could see the placement of his fingers on it prior to the pitch, to predict the flight, "ok this next one's going to be a curveball", and he claimed to be able to observe the spin of the ball by watching the stitching on the ball as it hurled toward him)
It's not just a matter of focal optics at that point. Your retina etc need to be similarly superior. Like a condor that can be riding thermals at 8,000ft and spot roadkill on the highway. Their eyes are a lot smaller than ours. Their cornea and lens are probably approaching perfection, but they've also got an incredible density of rods on their retina.
