Cross-dominance and the RSS Basic Handgun course (split form the LAV/AIWB thread)

[jlw]

I'm right hand dominant and was traditionally right eye dominant. I have astigmatism in both eyes, and it is worse in my right eye. I shunned the glasses that I was supposed to be wearing for a couple of decades, but now in my early-40s, nearsightedness set in and forced me to go to corrective lenses.

With my the lenses, my left eye is now trying to take over. If I draw to a target, I'm okay, but when I attended Rogers, I had difficulty in tracking the targets and then aligning the sights.

One of the instructors noticed this and put a strip of tape down the center of the left lens on my shooting glasses. This allowed my to use my left eye to track, but forced my right eye to take over when I was looking directly ahead. It worked

[uechibear]

<snip>

... I felt like I could speak to a few of uechibear's questions.

I have had the basic class several times...

<snip>

Thanks, Guys! Both of your answers were very helpful.

[cclaxton]

I am left eye dominant and right handed. I do find issues with sighting from time to time from certain angles. But if I was to change I can't imagine going to weak hand draw...the right hand is just so naturally responsive. I have considered trying to switch to right eye dominance just as a test. Maybe I will.
Cody

[Glenn E. Meyer]

Since we've been discussing the opinion of instructor X, Y or Z - I decided to browse the scientific literature. A casual look didn't find a specific study of eye dominance and handgun usage. There is a great deal of research on such with long guns (stressing military marksmanship and professional level shotgun sports). I've quoted a couple of abstracts to give you the flavor.

Jones LF 3rd, Classe JG, Hester M, Harris K
Journal of the American Optometric Association [1996, 67(2):73-76]
Type: Journal Article
Abstract Highlight Terms
Gene Ontology(1)
BACKGROUND: This pilot study was performed to determine the effect, if any, exerted by crossed dominance (contralateral hand and eye dominance) on the ability of novice riflemen to learn how to accurately shoot a rifle.

METHODS: Sighting dominance was used to determine the dominant eye. Hand dominance was determined by the arm used to shoulder the rifle in the shooting position. Subjects were 308 military recruits at the Fort Benning Army Base in Columbus, Georgia, who had undergone basic training in rifle marksmanship. Qualification scores obtained at the base rifle range were used to measure the subjects' ability to learn marksmanship skills.

RESULTS: The subjects with right-hand/right-eye and left-hand/left-eye (uncrossed) dominance had qualification scores that were significantly higher (p =.009) than the subjects with right hand/left-eye and left-hand/right-eye (crossed) dominance. A significantly higher percentage of subjects with uncrossed dominance achieved rifle qualification (86.1 percent) than subjects with crossed dominance (56.5 percent) (p =.000).

CONCLUSIONS: The learning of rifle marksmanship is influenced by eye dominance. Individuals who shoot right handed and are left-eye dominant or who shoot left handed and are right-eye dominant do not learn marksmanship skills as readily as individuals who have matched eye and hand dominance. Since crossed hand and eye dominance can be easily determined, it should be possible to identify cross dominant individuals and provide them with special training so that they can perform at a higher level of skill.

http://oai.dtic.mil/oai/oai?verb=get...fier=ADA611755

Abstract : This study evaluated the combined effects of a shooter s anthropometric dimensions, weapon design attributes, firing position, range, and sex on marksmanship. The US Army Research Laboratory M-Range live fire test facility was used to conduct the study. Study participants consisted of a random sample of 26 Army Soldiers recruited from the US Army Research, Development and Engineering Command Solider Support program. The study participants fired the M16A2 rifle, M4 carbine, and the Heckler & Koch (HK) G36 weapons that feature different barrel lengths and weights. Shooters were asked to fire at 50-, 100-, and 150-m targets. The multiple regression analysis indicated a high degree of correlation among the independent variables; however, the results also indicated that isometric strength, hand length, and rightward horizontal neck rotation may predict shooting performance under time pressure while firing from either a reflexive firing position or a prone firing position. Shooting performance was measured in terms of hit ratios and the radial error from a designated aimpoint. A multiple regression analysis was performed to develop a mathematical model that expresses shooting performance as a function of associated anthropometric data, weapon design data, firing posture, range and sex.

I suggest as before, that a similar sophisticated analysis is needed to determine the general effects and specific training processes for the handgun level of practice. The military or professional competition may have the time needed for intensive training for cross dominance. It is not clear to me how a class for beginners or intermediate folks who don't practice intensively would affect performance enhancement to reach an unconscious and automatic compensation under real stress. Would a detriment occur? Is it better to have a dominant hand and nondominant eye or vice versa? What are the individual variations in the effect of training? Does it work for some and not others? Is this determined by accurate measurement of dominance and performance? Does a level of mismatch based on such an analysis predict better performance than a switch of hand or eye? How does this interact with level of training?

Without such, I would be reluctant to accept as dogma an instructor saying that one should switch hands. I'm fairly decent shot with each hand - in fact, I shot a couple of classes fairly well with my nondominant hand (broke the other wrist) - so what? Being a lefty, mabye I'm mixed or just special. Such a study takes bucks, equipment and time. The services might do so, if they thought handgun usage was that important. If such a study is out there, it didn't come up quickly but let me know if you know of one.

[dgg9]

Glenn, great info. The obvious specific difference of course is that with a rifle, you generally have to shoot with one eye or the other. Handguns are usually always shot with the dominant eye, although admittedly with some contortions. Non scientific, but in my personal experiences at classes I would say 10% of shooters are cross dominant but I didn't see any obvious differences in ability. That suggests to me the effect is not major. And as I mentioned before, it's one factor among several.

[Mr_White]

Non scientific, but in my personal experiences at classes I would say 10% of shooters are cross dominant

I don't have any more scientific a basis for this than you, but my sense is that about 1/3 of the people I see in class are cross dominant.

[Glenn E. Meyer]

See if this works for a review indicating the concept is ill defined - http://link.springer.com/article/10.3758/BF03194802

Abstract

We examine a set of implicit and explicit claims about the concept of eye dominance that have been made over the years and note that the new literature on eye dominance does not reflect the old literature from the first half of the last century. We argue that the visual and oculomotor function of the dominant eye—defined by such criteria as asymmetry in acuity, rivalry, or sighting—remains unknown and that the usefulness of the concept for understanding its function is yet to be determined. We suggest that the sighting-dominant eye is the eye used for monocular tasks and has no unique functional role in vision.

Perception & Psychophysics
February 2003, Volume 65, Issue 2, pp 310-317
What does the dominant eye dominate? A brief and somewhat contentious review

Alistair P. Mapp, Hiroshi Ono, Raphael Barbeito

I take away what I said before, I'm not convinced that forcing someone to go the nondominant hand to line up with dominant eye is the best for handguns. I'd like to see it tested in a rigorous fashion.

For a beginner, is it worth the motor skill loss (if such exists) in common handgun usage?

[GJM]

You can beat this subject to death, and I have in the past, but the answer is, there is no one right answer for everyone.

Cross eye dominance is an impediment. The impediment can be overcome, and there are at least three different approaches to doing so. Enos, Sevigny and Leatham being examples of three ways to solve it.

[SouthNarc]

Has anyone personally experienced a change eye dominance as they get older?

[GJM]

Has anyone personally experienced a change eye dominance as they get older?

I did, temporarily, when recovering from a retina problem. It happened automatically -- the hard part was learning to present the pistol under my left eye drawing. Even now, if I get a bright light, as in a reflection or bright sunshine into just my right dominant eye, my brain tries to switch to the left.

I have heard of some people switching eye dominance when fatigued, or due to an injury. For folks not strongly eye dominant, I think switching back and forth is more common.