I am basically right-handed with left eye dominant. When I started shooting in the mid-60's with the CU team, the coach had me wear an eye patch over my left eye. Later, in the service, I was taught to focus using my right eye and ignore my left.
Now, in my 70's, I have developed the habit of slightly squinting my left eye to focus on my right. Yeah, it causes fatigue and probably reduces my ability, but I still have fun.