We deal with cross dominance in our classes frequently-testing for it is one of the first steps in marksmanship training. Every instructor course I have attended has a component of non-dominant hand shooting, and always extracts groans from the students. Here you are dealing with vision, as well as dexterity and strength issues with the non dominant hand. Once you know you have cross dominance, it is simple to compensate for. There are several strategies. One that is used most often is to simply close the dominant eye, thereby forcing the non dominant eye to do the work with the dominant hand. Of course you lose some of your peripheral vision when you do that. Another method is to adjust the presentation of the pistol over to the dominant eye-we are only talking about a couple inches. Most recently red dot sights on pistols have come into favor. One advantage of the RDS pistol sight is that eye dominance doesn't matter-you leave both eyes open, focus on the target, and put the red dot in the middle of the target