Eye dominance in shooting is a phenomenon which attracts many differing opinions and it can often be rejected by shooters and coaches who do not fully understand it. My interest came from years of personal frustration with my shooting, trying to understand what going on with my eyes. I tried everything on the market, but nothing seemed to work for me. One thing I realised early on was that I could not shoot efficiently with both eyes open, no matter how many people told me to "focus on the target". As a professional engineer and shooting coach, I needed a detailed scientific answer that I could relate to, and consequently impart to clients and students on courses. In particular, I wanted to know why I saw a double image of a gun when focusing on the target, and why some of my colleagues did not.
Very talented shooters tend to have a strong dominance in their Master eye which undoubtedly contributes to their success. There are exceptions of course, but in general the ability to shoot with both eyes open along with a strong master eye that matches handedness, is a good foundation for success. For us lesser mortals, these conditions are not naturally occurring so I firmly believe it takes a good coach to properly diagnose and explain the issues in order to arrive at the most appropriate remedy for their client. The problem is exacerbated by the many different variations and manifestations that can confuse the best of us. It is also important to note that a remedy for one shooter may not necessarily be suitable for another, and the explanation required will also need to be tailored to suit individual needs. The following piece is based on personal experience and much research. There will be some that disagree, but I hope that many will identify with the examples and reasoning behind it.
The three main optical areas which can affect a shooter are as follows:
The shooter sees double images of the gun when fully focusing on the target.
- This can confuse the shooter causing a tendency to look back at the gun to remove the blur.
- The shooter can often instinctively close the off eye to remove the second image.
- Inconsistent application of lead.
The gun is favoured by the off eye and the head tilts over the gun
- Often mistaken for a cast issue
- The gun will not always point to where the shooter is looking
The gun is favoured by the off eye and the gun moves across into its line of vision.
- The gun is not pointing where the shooter is looking.
To better understand all of these issues, we need to start with some of the basics and use some standard terminology.
When your eyes look at a single object, they simultaneously converge inwards towards each other until they both are fixed on the object. Because you have two eyes and they are a few inches apart, your brain receives two slightly different images of the object which it then cleverly combines to make a single 3D image. This is known as binocular vision and the resulting image is known as a stereoscopic view. This view is produced by the fusion of these different images, giving us our ability visually perceive depth and distance.
The term Binocular disparity refers to the difference in image location of an object seen by the left and right eyes. This results in the eyes' horizontal separation or parallax. The brain uses this disparity to extract depth information from these two-dimensional retinal images. In short, having two eyes focused on an object allows us to effectively triangulate its position.
Because of the distance between your left and right eyes, each eye perceives the object from a slightly different angle. If an object is far away, the disparity of that image will be small and if the object is close, the disparity will be large. The diagram below shows how each eye receives an image from a slightly different angle in order to create a 3D image.
If you now raise an object (i.e. a Gun) into your view whilst continuing to look at a distant object, this can result in Double vision of the gun. When relating this phenomenon to shooting, the distant object is of course the target and anything that appears in the foreground, (the gun) will not be seen with binocular vision because the eyes remain fixated on the distant object.
The framing test below can tell you whether both your eyes are "balanced" in equal amounts using your binocular vision. Centre your nose facing an object in the distance (in this case a clay, but it can be any spot on a wall). Focus your eyes on the clay and put your thumb up in front of your nose pointing at the clay. Continue to focus on the clay. If both eyes are balanced, you will see two slightly blurred thumbs framing a focused image of the clay.
Eyes focused on the clay, with a single thumb pointing at the clay
Now, switch your focus to your thumb. You should see two solid slightly blurred clays framing a sharp image of your thumb.
Eyes focused on the thumb, with a single thumb pointing at the clay
Can’t see two thumbs (or two clays)? Or do you see two thumbs, but one thumb is blurrier? Or does one thumb appear faint like a ghost image? These are all possible outcomes for shooters with differing levels of binocular vision and can also indicate eye dominance. Shooters who see two images normally present as having central vision during the finger pointing test. Shooters who have a strong dominance in one eye can sometimes also see two thumbs, but one is normally much stronger than the other. Some shooters who are extremely dominant in one eye may not see a second image at all. Great for shooting if the dominant eye matches handedness!
Someone with central vision will often see two blurred barrels when focusing on the target. This can be extremely frustrating, especially if trying to determine any forward allowance. The shooter may subconsciously look back at the barrel to reduce the double vision or try to get rid of the blur. A coach should look for their client shutting their off eye involuntarily as this could be an indication that they have double vision of the gun. The images below show what a shooter with differing dominance levels can see when fully focusing on the target and applying lead. (A right to left crosser in this case).
The images below further explain the concept of binocular disparity and how it can affect a shooter. Image 1 shows a right handed shooter with a dominant right eye. For the purpose of this demonstration, let’s assume the target is stationary or has no lateral movement and of course it is not to scale. We can see that the shooters master eye is aligned through the gun representation, and both eyes have converged and are fixated on the clay. The darker shaded section shows how the eyes are focused on the clay using their binocular characteristics. The lighter section shows some of the peripheral vision also available to each eye. The red dot indicates the end of the gun or “bead”.
You will see the images presented to each eye caused by the binocular disparity. Each eye has a different view of the gun in relation to the target, so in the final combined image, there are two beads, but the image to the dominant eye is stronger. In a shooter with very strong dominance, the faint image can even disappear.
Image 2 shows a shooter with Central Vision. You will note the gun has settled between the two eyes and the resultant image presented to each eye sees the gun on a different side of the target. Once the brain combines these two images together the final image seen by the shooter has two images of the gun. It wouldn’t take too much imagination to work out what the picture would look like if a right handed shooter had a strong left eye dominance with the end of the gun effectively now moved across to the off eye.
We have concentrated a lot on Binocular disparity and resultant double images, but as I said before not all shooters suffer in the same way. We saw in the previous section that someone with a very strong dominance may not see a double image, but this is also true for some with varying degrees of dominance. This is not a binary phenomenon. In a shooter that has a strong dominance, the brain makes a choice and can reject all or part of the information from one eye of the eyes.
Unlike rifle shooting where there is both a foresight and a rear sight to align the gun with the target, the shotgun effectively utilises the shooters eye as a rear sight. Consequently, if this eye is in the wrong position in relation to the gun, it will adversely affect the fall of shot. For example, if the head is too high on the stock, the end of the gun will raise to align with the target and the shot will be high. Using the same rationale, the eye that is over the rib, the "Master Eye", must be dominant in order for the shot to go in the direction where the shooter is looking. If the "off eye&", or eye which is not over the rib, is dominant then it will effectively incorrectly identify the target through the end of the gun from the "off side". This is best explained using the diagrams below. Again the diagrams are not to scale but you can see how the off eye is dominant and has influenced the position across the face and he perceives the gun to be lined up correctly before the shot is taken.
The Off eye is viewing the target through the end of the Gun pulling the gun across the face.
The second picture shows another manifestation of the problem where the shooter tries to move his head over so that the off eye can look fully down the gun. This can look like a cast problem to the unaware.
The Off eye is trying to view the Target tilting the head across the top of the gun. The result can vary but in this case the shot will go high and left.
There are various methods of identifying eye dominance in an individual; pointing a finger, using the gun or watching the client shoot. There are arguments for all of these methods, but the finger pointing method can give you a very quick indication of any potential issues before moving on.
Finger pointing. This method is carried out by the shooter with both eyes open standing about 2 metres away from the coach. The shooter then points swiftly to the coach’s master eye, which should be repeated a few times to ascertain an average reading. The coach will then determine the shooters finger position in relation to their eye in order to accurately gauge the effect of “off eye” when aiming the gun. The Images below show what the coach is looking for and how this information can be used. You will note from the images that there are varying degrees of dominance and that it is not a binary phenomenon. I.e. Not just left or right. Be careful when using techniques such as a hole in a card moved towards the eye to determine eye dominance. This will give you a binary answer of left or right even if you have central vision.
With the gun. The finger pointing method is just an indication of a potential issue. When the gun is placed in the shoulder, sometimes things look very different. I suppose it’s not surprising that when you put a large metal object under your eye, things might change! This techniques requires the client to point a closed gun which has been proved to be empty towards the coach’s finger, which is in front of his/her master eye. The coach will then move the finger towards the shooters off eye and then back again to see of the off eye influences the gun position.
Whilst Shooting. This method is often used by corporate instructors who do not have the time to spend on too much off range work. It also relies on quite a bit of experience to identify quickly, particularly if the shooter is engaging a fast crossing target. Normally the phenomenon can be identified using a simple target with not lateral movement. A right handed shooter who is left eye dominant would potentially miss up the left hand side of the target. If the coach identifies the problem, it will still need to be dealt with which supports the argument for doing this work off range before shooting.
For novices we tend to use a prescribed method to correct any issues (tape on glasses or close the “Off” eye throughout the shot). This ensures a basic approach is effective and saves time, but the coach may prefer to use one of many other techniques or products on the market to solve these issues. These methods include squinting the off eye just before the shot is taken, placing the thumb on the barrel to obscure the bead from the off eye or there are many products that can be either attached to the barrels or the glasses.
Shooters enjoy differing levels of success with these techniques and it is important to point out that there is no “one size fits all”. I mentioned earlier that many do not fully appreciate eye dominance and my experience is that they are generally so dominant in their master eye, they find it difficult to comprehend how it affects those that are not. In addition there is a perception out there that “Clay shooters should always keep both eyes open”. This statement without the correct context is unhelpful and not necessarily true. The problem is that having both eyes open has enormous benefits to clay shooting (depth perception and increased peripheral vision being two of them), but the conditions need to be right. I once sat in a conference given by an elite shooter and a member of the audience asked the question, “do you shoot both eyes open?” and the answer was “yes”. The person who asked the question looked satisfied with the answer and we moved on to another subject. It struck me at the time that the message received by the audience was that everyone should shoot both eyes open. There was no mention of eye dominance and the necessary context.
There are many eye dominance correction products and methods on the market. A coach needs to have a good understanding of the pros and cons of each product.