I'm right eye dominant... 20/20 in my right eye, 20/40 in my left. For years {pistol shooting}, I've shot right handed, using my right eye, but had to deal with a fuzzy front sight picture. A diopter helped, but I still went back to fuzzy front sight shooting. Now...during daylight hours, I still shoot right handed, yet, I have trained my mind to focus the front pistol sight with my left eye, with no fuzzyness; and using my right eye to focus on the target with one image of the sights and target in my mind.
For fast reactive shooting --- I still go back to fuzzy front sight shooting --- the same for shooting in dark places, like an indoor range; where the clear front sight picture does not work in the dark.