Your dominant eye is the eye your brain prefers for processing sight information. You need to know which eye your brain prefers so you can position the gun’s sights for your dominant eye. Site alignment usually happens unconsciously without much thought, as your brain already knows which eye it trusts.
Why do we need to know which eye the brain trusts?
Because it will help you and your brain be more accurate and consistent at speed.
Most people have a dominant eye that is the same as their dominant hand. Two-thirds of the population are right-eye dominant, and one-third are left-eye dominant. A few people have no eye dominance, so you will want to check and understand which type you are. Many people are not aware they have a dominant eye until they are tested.
How to Test for Eye Dominance
Pick an object that is around seven yards away and about the size of a doorknob or light switch. Bring both hands up and form a triangle window that frames the object. With both eyes open, extend your arms, keeping the object or target centered inside the triangle window. Next, close each eye one at a time and hold your triangle window in the same position without moving it. Start by closing your left eye and noting what you see. Then open your left eye and close your right eye, noting what you see. Whatever open eye you saw the object framed inside your hands is the one your brain trusts the most. This would be your dominant eye.
You can do these tests under different conditions and at different distances to see what your brain prefers so that when you mount your gun and form a sight picture, you can do it quickly and accurately.