I also have the same problem but over time I have trained my eyes to adjust correctly without haveing to close one eye. The problem is that I am letft handed and do everything lefthanded except for shooting a bow and gun. I started out having problems when I started duck hunting 10 years ago. I was always looking down the barrell sideways with the left dominant eye. That in turn was throwing my shot off. What i did was took a pair of shooting glasses and put some tape over the left lense and shot for over and over at skeet and evenhuntinglike that leaving both eyes open. After about 2 months of this I was able to take the glasses off and had no problem. If my shooting would get off I would stick the glasses back on for a few sessions of shooting to remind my brain what it had to do. I then incorporated this into my bow shooting with a eye patch and it only took about a week for me to get it figured out. This is what worked for me and maybe could help you out. OH and before I did this with a gun I was shooting 70 out of 100 trap. Know I have gone 100 for 100 more than I can remember and i average 97 out 100.