Greetings Shooters,
Experienced shooters have contacted me about the subject of eye dominance and I would like to share some of my knowledge as an eyecare professional and as a bullseye shooter. I haven't read what others have written on this subject in relationship to bullseye shooting and I always try to write about information that is understandable and easy to relate. Others may have different viewpoints on this subject matter.
Let's have some fun with this subject, shall we? If you guys had a choice of looking at a boring bullseye or an attractive woman, which would draw the most attention? I don't know about you but I do know where I'm going to look. (Feel free to switch genders and in any sequence so that I may be politically correct and I don't intend to offend anyone). My point here is that our brain would shut off unimportant images and concentrate on the important ones. A little more on suppression later now that I have your undivided attention.
When I first learned to shoot a 1911 .45 cal. pistol in the service, I was taught to use the eye to see the sights which matched the dominant hand. I'm right handed so I should have sighted with my right eye and was told that all top shooters did this. I struggled to use my right eye and the sights did not seem stable as it faded in and out. Since I had an inquisitive mind and I always questioned authority, I found out that I was left eye dominant and started to shoot using my left eye while using my right hand to hold the gun. I then shot very naturally and effectively.
The easiest way to determine your eye dominance for those who are new to bullseye shooting would be to reach out your arms in front of you, bring your hands together with the palms facing outwards and form a small 1" opening between the web of both hands. Next, pick out an object across the room and look at it through the opening of your hands. Stop and check which eye you are viewing with. Repeat this several times and you'll probably note that you are using the same eye every time. This is your dominant eye. If you move the opening of your hands so that the opposite eye is seeing (the non-dominant eye), it may feel quite awkward.
I would advocate shooters to try shooting with their dominant eye along with their dominant hand, whether the right or left. This is natural and you do not have to fight with your eyes. This may be counter to what you were taught but this trial experiment costs nothing and requires no additional equipment. How many shooters have spent hundreds or even thousands of dollars on toys which only had a minor improvement on their scores?
When your eyes are working well, your hand-eye coordination improves and sustained fire will be easier as you regain aim between shots. I would suspect a less noticeable difference with slow fire. The New Jersey state champion said it best with, "Buy as many points as you can, you have to shoot the rest." I believe you can shoot the rest BEST with your dominant eye. If you have been using your non-dominant eye and decide to shoot with your dominant eye now, improvements may not come overnight because of other factors such as a possible shift in stance and body position. However, when eyesight is stable, one can concentrate on other fundamentals and not be concerned with stable focus.
Now I will tie in my attractive woman into this discussion of suppression. Our brain dislikes confusing images and would always try to allow vision to be "not unsettling." Our brain would favor vision from our dominant eye and ignore vision from our non-dominant eye whenever there is a disparity. Kids who have a crossed-eye will have their brains shutting down vision to the affected eye so that double vision would not confuse the child. However, AMBLYOPIA will develop quickly (Please refer to my article on this important subject). Shooters using the red dot scopes should try to use their dominant eye to view the dot. I see this dot so naturally with my left eye (even though I'm right-handed) that I don't need to occlude my right non-dominant eye. My brain would suppress the scope image of my right eye. Others may need an occluder to cover the non-dominant eye.
Let's try this experiment. Look at a small object across the room such as a light switch or doorknob. As you continue to look at this object, raise your right thumb in front of your eyes and you'll see two thumbs. Position your thumb so that the distant object is between the two thumb images but continue to look only at the distant object. After several seconds, notice that the brain will try to shut off one of the thumb images. This is suppression.
Since I started using red dot sights, my left dominant eye always had a strong image of the bull along with the dot as I suppressed my right eye, without the need for an occluder. I began with an occluder but I quickly found that my shooting was easier without it. During every practice and every match, my right eye stayed suppressed until ONLY ONCE recently, when I shot next to Ed Masaki at the Koko Head Shooting Complex in Honolulu, Hawaii. In all the ranges I've shot in, there were always uninteresting backgrounds such as barren hillsides or an open field such as in Camp Perry. In the Koko Head complex, the background was tall, multi-shaded grass waving as the winds blew against the hillside. During one timed fire session, my brain decided that vision from my right suppressed non-dominant eye was more important and so much more interesting than the bull from my left dominant eye that my eyes switched dominance, and for 5 seconds, the bullseye was fading but I saw a lot of waving grass. This took me by surprise but after a few blinks, I was back on track.
What I have just discussed will lead into my next comments which may seem controversial to some. Oxygen deprivation and carbon dioxide buildup have been mentioned on this list as a cause for the vision to go out of focus. It would be safe to state that very few of us would hold our breaths for a full 20 seconds during timed-fire. I normally shoot my timed-fire in 10 to 12 seconds and many have stated on this list that they take a breath in the middle of timed-fire. So how could holding one's breath for 5 to 10 seconds or even 20 to 30 seconds cause enough oxygen depletion and carbon dioxide buildup to have physiological influences?
I now postulate that what has happened to many of us could have been "Alternating Suppression" and since it happened to me in Hawaii, I understood what had occurred. Let's try the thumb exercise again but this time stare for a longer period of time. Now you will note that sometimes the left image will fade and then the right image will fade. This is alternating suppression and this may be one of the mechanisms for the sight picture disturbance whether it be the dot or iron sights. Those who use an occluder may experience the occluded eye "wanting to see," in which case, you might have noticed your vision turning black or white, depending on the shade of the occluder. THE SIGHT PICTURE DISTURBANCE MAY BE MORE PREVALENT IF ONE USES THEIR NON-DOMINANT EYE TO SIGHT. I further experimented by viewing my eye chart in my exam room and holding my breath for 45 seconds. I did this under a variety of circumstances and not once did the eye chart go out of focus DUE TO LACK OF AIR although something else occurred which I will discuss at a later time.
Others may offer different viewpoints on these related subjects but that's what Bullseye discussion is all about. There is more than one way to sight and fire your pistols and I'm offering some ideas. Certainly, each of us may have different degrees or magnitude of eye dominance and suppression, and some may shoot just as well with either eye, especially during slow fire.
Good Vision and Good Shooting To All,
Norman H. Wong, O.D.