Your Dominant Eye
Regardless of whether you are shooting a rifle or shotgun, you will first need to determine your dominant eye. The dominant eye is the eye you use for sighting purposes. It is the stronger of your two eyes, and it’s the one that judges speed and range, and focuses more accurately than your non-dominant eye.
Most right-handed people are right-eye dominant. Most left-handed people are left-eye dominant. Some people are cross-dominant. They are right-handed, but left-eye dominant, or vice-versa. If you are cross-dominant, your instructor may wish you to mount a rifle or shotgun on the shoulder of the dominant eye regardless of your dominant hand. This adjustment can make the difference between hitting and missing a target.