This topic gets so much discussion steeped in dogma that it is usually very confusing to most new shooters.
The truth is this: Do what you need to do to see your sights well enough to make an acceptable hit on the target. It does not matter what you do to your eyes to get there. Keep both eyes open, or close one eye, or tape your glasses, or wear an eye patch and a parrot on your shoulder.
It does not matter.
Personally, I get far too much visual confusion when I keep both eyes open, so I close an eye. I shoot just fine.
I find that I get more visual information with both eyes open. It was confusion at first but over time my tiny mind has figured out how to interpolate the two eyes info. I don't think that it was any coincidence that my initial two eyes open success was with a pistol at closer fields of range. I just kept adding more range. With a pistol I find that I have to close an eye at the 25 yard mark. With a scope I find that I close an eye if my magnification isn't right for the shot. My eyes, my brain, I know that others will differ. There are benefits to both eyes being open if you are able to process what they both see. Some days are better than others...


















































