Both-Eyes-Open sight picture - what is correct?

[Karl]

In training, and just about all over the Internet, you keep hearing "focus on the front sight" to get a good sight picture. However, with both eyes open, this is too vague an instruction - there are multiple mechanisms at work to focus with both eyes open. Here's a picture to help illustrate what I'm talking about:


Link to picture in case embedding fails: http://i.imgur.com/eUzWR.png

Obviously, A, E, and I are the three most likely pictures to choose from, as it is difficult to accommodate your eyes to a different focal plane than the one to which they are converged (this is why Magic Eye images are frustrating).

If you tell the novice shooter just to "focus on the front sight", chances are they'll end up at picture E. This creates the obvious problem that you now have two images of the target. In a high-stress situation, would a shooter be able to discriminate between the two images, particularly if the target appears similar to their surroundings, due to camouflage or bystanders?

I would argue that A is a superior sight picture to train towards, because it allows you to (1) Keep all of your focus on the target and easily track them as they move, and (2) train to line up "all of the leftmost images", and ignore any spurious images to the right (flip left-right for left-eye dominance). With picture E, you have to train to ignore the right image of the rear sight, and the left image of the target.

I am relatively new to all of this, so I would like some clarification from those more experienced: Which sight picture would you train towards, and why?

[Merc1138]

I don't understand this chart at all. I'm right eye dominant, and I don't see 2 targets when focusing on the front sight with both eyes open. I do see the rear sight off to the right, but it's not just a matter of that image being out of focus, it's almost transparent if that makes any sense.

This chart is ignoring how your brain stitches 2 images together for stereoscopic vision(which doesn't always work perfectly with things too close to your face). If this chart were correct, you would always be seeing two of everything.

Keeping two eyes open is not vague at all. Extend your arm in front of you, now extend your finger. Focus on the tip of your finger. You should not see doubles of anything including the wall, monitor, or whatever is beyond your fingertip. Move your finger closer to your face in front of your nose, keep focusing on it. You shouldn't see double until it's within a foot or so(and the closer you get, your eyes end up having to cross to prevent seeing double when you get close enough, just try focusing on the end of your nose and it should be obvious).

If this chart were correct, then you wouldn't be able to read the chart without seeing double.

[fiddletown]

[1] I shoot with both eyes open and learned focusing on the front sight when I started. I've been doing it ever since. And I focus on the reticle when shooting a scoped rifle (with both eyes open). (Of course, I focus on the target when "wingshooting" with a shotgun.)

[2] I've never had a problem with sight picture. I've taken a pretty fair amount of training at places like Gunsite and shot USPSA and Cowboy Action competition, and a flash sight picture with a focus on the front sight has worked well for me.

[3] I'm an NRA certified instructor and have been helping teach Basic Handgun classes for beginners for a number of years. I guess I've worked with several hundred students. We teach focusing on the front sight. Students seem to get the hang of it and wind up shooting quite well.

[Karl]

I don't understand this chart at all. I'm right eye dominant, and I don't see 2 targets when focusing on the front sight with both eyes open. I do see the rear sight off to the right, but it's not just a matter of that image being out of focus, it's almost transparent if that makes any sense.

Likewise, there is an image of the target to the left of the front sight.

This chart is ignoring how your brain stitches 2 images together for stereoscopic vision(which doesn't always work perfectly with things too close to your face). If this chart were correct, you would always be seeing two of everything.

You do see two of everything that is not in the convergence plane. Your brain has learned to trust one eye over the other for everything not in the convergence plane, and that eye is called the "dominant" eye.

Keeping two eyes open is not vague at all. Extend your arm in front of you, now extend your finger. Focus on the tip of your finger. You should not see doubles of anything including the wall, monitor, or whatever is beyond your fingertip.

This is incorrect - you will see doubles of everything in front of, and behind, the convergence plane. The distance between the double imagery will vary with the ratio of the distance from the convergence plane to the object in question, divided by the distance from your eyes to the convergence plane.

Move your finger closer to your face in front of your nose, keep focusing on it. You shouldn't see double until it's within a foot or so(and the closer you get, your eyes end up having to cross to prevent seeing double when you get close enough, just try focusing on the end of your nose and it should be obvious).

You are describing convergence failure, where the object is so close that your eyes cannot possibly move close enough to converge the two images of the object.

If this chart were correct, then you wouldn't be able to read the chart without seeing double.

No, because the chart exists in a single focal/convergence plane.

The issue with focus as it pertains to sight picture is that there are three planes at work, and you can pick one plane to converge on (everything in that plane will appear as a single image, everything in a different plane will appear double and slightly transparent), and one to accommodate on (everything in that plane will appear crisp, and everything in a different plane will appear blurry). If you converge and accommodate to the front sight plane (scenario E), then you will have double images of the target and of the rear sight. They will be semitransparent images, but there will still be two of each. That's the reason why you'd want to shoot with one eye closed for accuracy, because it eliminates all of the double imagery, but you trade off situational awareness.

[Karl]

[1] I shoot with both eyes open and learned focusing on the front sight when I started. I've been doing it ever since. And I focus on the reticle when shooting a scoped rifle (with both eyes open). (Of course, I focus on the target when "wingshooting" with a shotgun.)

[2] I've never had a problem with sight picture. I've taken a pretty fair amount of training at places like Gunsite and shot USPSA and Cowboy Action competition, and a flash sight picture with a focus on the front sight has worked well for me.

[3] I'm an NRA certified instructor and have been helping teach Basic Handgun classes for beginners for a number of years. I guess I've worked with several hundred students. We teach focusing on the front sight. Students seem to get the hang of it and wind up shooting quite well.

Thanks for your feedback. You've taught a lot of classes, so you have probably seen a lot of setups where you have 10, 15, 20 identical targets all set up in a row. At longer ranges, if you focus on the front sight, then all of the targets will appear blurry and overlapped. How do you pick out the correct target while remaining completely focused on the front sight with both eyes open?

[Merc1138]

Likewise, there is an image of the target to the left of the front sight.



You do see two of everything that is not in the convergence plane. Your brain has learned to trust one eye over the other for everything not in the convergence plane, and that eye is called the "dominant" eye.



This is incorrect - you will see doubles of everything in front of, and behind, the convergence plane. The distance between the double imagery will vary with the ratio of the distance from the convergence plane to the object in question, divided by the distance from your eyes to the convergence plane.



You are describing convergence failure, where the object is so close that your eyes cannot possibly move close enough to converge the two images of the object.



No, because the chart exists in a single focal/convergence plane.

The issue with focus as it pertains to sight picture is that there are three planes at work, and you can pick one plane to converge on (everything in that plane will appear as a single image, everything in a different plane will appear double and slightly transparent), and one to accommodate on (everything in that plane will appear crisp, and everything in a different plane will appear blurry). If you converge and accommodate to the front sight plane (scenario E), then you will have double images of the target and of the rear sight. They will be semitransparent images, but there will still be two of each. That's the reason why you'd want to shoot with one eye closed for accuracy, because it eliminates all of the double imagery, but you trade off situational awareness.

Yes, that's all correct, and your brain does it all automatically for you(which is what I said).

If your brain did not do this, then whenever you drive a car and focus on the vehicle in front you, then you would have double vision of everything else ahead of the car you're looking at, and between your face and the car you're looking at. Because your brain process everything correctly, this is not the case(if it is, then you need to see an optometrist or something). It is exactly the same as focusing on the front sight post of a handgun with your arms extended. Your chart is clearly ignoring this. I don't understand why you would think that focusing on the front sight of a handgun would be any different than focusing on any other object with two eyes open.

[Karl]

Yes, that's all correct, and your brain does it all automatically for you(which is what I said).

If your brain did not do this, then whenever you drive a car and focus on the vehicle in front you, then you would have double vision of everything else ahead of the car you're looking at, and between your face and the car you're looking at. Because your brain process everything correctly, this is not the case(if it is, then you need to see an optometrist or something). It is exactly the same as focusing on the front sight post of a handgun with your arms extended. Your chart is clearly ignoring this. I don't understand why you would think that focusing on the front sight of a handgun would be any different than focusing on any other object with two eyes open.

Your brain does most of it automatically, not all of it. When driving, there is never a need to precisely align three objects in three different focal planes, so your eyes constantly dart around, focusing intermittently on the information that is important. Forming a sight picture is a different activity - while you are indexing the firearm, you shift focus from target to the front sight, and are expected to maintain focus on the front sight while you form a sight picture. If your target moves a significant distance, or if he moves into a crowd of similarly-dressed people, sight picture (A) gives you the visual acuity to continue following the target, whereas (E) could potentially mess with target acquisition (see training scenario I cited in post 5).

The answer could be "you need to learn to index your firearm so well that you're never pointed at the wrong image while focusing on the front sight". I don't know if it is. What I do know is that binocular vision does create double images of everything that is not in the convergence plane. Eye dominance suppresses, but does not eliminate, one of the images. It is faint, but it is still there. (See https://en.wikipedia.org/wiki/Binocu...ness_of_vision) For people with roughly equal eye dominance, the double image may not be suppressed at all.

However, I'm mostly concerned about the tactical implications of sight picture (E). If you have a moving, dodging target, wouldn't you want to be focused on the target? And, if you can index your weapon extremely well, why would you need to focus on the front sight to align it, rather than just aligning the blurry sights?

[ElDub1950]

I look for this topic in discussions because I'm right handed and very left eye dominant. The more I learn from others, the better I am. The discussions usually center around the 'double vision' effect.

Seemingly most people do experience the effects as you describe but it is not a blanket statement. With both eyes open I do not get the double image effect UNLESS I intentionally try to acquire the target and get a sight alignment with my non-dominant eye which of course would throw my shot off far to the left.

By simply turning my head a few degrees to the right while bringing my gun to ready position, I eliminate the initial point of aim being off because of the cross dominance.

I've wondered if most cross-dominant people experience this double image effect to a much lesser extent. Possibly because the brain has spent a lifetime making this adjustment? Any feedback from other cross-dominant shooters?

As for training, for me, both eyes open is for defensive mode. That being the case, the initial target acquisition (going from low ready to on target) has to be while focused on the target and you have to be able to shoot the instant you have acquired the target. Spotting a threat, bringing your gun to ready, then refocusing on the front sight and adjusting your sight alignment causes too much of a delay.

I dry fire practice by quickly acquiring the target and taking the shot, then hold it to refocus and verify my sight alignment. It doesn't take long before your instant point of aim is consistently good.

So, that's what works for me. Your mileage may vary.

[BigFatGuy]

I tend to focus on the target. At an indoor range I get such bad double-vision that the target next to me appears to be directly on top of my target if I don't.

I also figure that I'll be looking at the target in a self-defense situation.

I may not get crack-shot precision, but I can hit a dessert plate.

[Ziggy91]

Forget the diagrams, you're taking this too seriously.
First hand experience is the best way to learn. Go out and shoot to see what makes sense to you.

[9mmepiphany]

I think, while you have a good understanding of vision and convergence, you misunderstand aligning handgun sights and focusing on the front sight.

You don't do it with both eyes, you sight by aligning the sights and target with the dominate eye and...for lack of a better word...ignoring what your other eye sees. You actually aren't ignoring it, you are simply perceiving the information with your subconscious.

You actually don't look at the rear sight, you just look through the rear notch...that is why 3-dot sights are more a hindrance than an aid in rapid sight alignment.

You look at the front sight blade and place it over the target. In a defensive situation, you would switch you focus back and forth between the target and the front sight...with you focus on the front sight as you make the final press of the trigger.

As you become more a more skilled shooter, you see the aligned sights without looking at them....it is what martial artist call soft eyes. You leave the perception of them being aligned to your subconscious and allow that to cue your trigger press.

An old target shooter's trick to develop the skill of of only looking through the dominate eye is to place a piece if translucent tape, on the lens of your shooting glasses, covering the non-dominate eye.

Shooting with one eye closed, besides adding stress, also induces adverse effects to your ability to focus with your open eye

[CDFingers]

The "wingshooting" comment is most like what I do with a hand gun at closer than about 20 feet: the original point and click interface.

CDFingers