Eyesight, sights and iris

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UnGe
Posts: 161
Joined: Tue Mar 02, 2021 4:24 pm

Eyesight, sights and iris

Post by UnGe »

My dominant eye is much weaker than a non-dominant one. It has a "good shooter astigmatism" - the only distance it can focus well is a front sight one, so I do not need any correction for it.

But as my non-dominant one is better, brain constantly fights for the eye control. I added a "scotch blinder" and I believe things improved, or at least became easier for me. The next area I wanted to address was that the target was very blurry, I think much more than for anybody with the normal eyesight. As an experiment I've added a stick-on iris, and here I got a bunch of surprises.

- With everything more clear it became much harder to focus on the front sight
- Sights gap that I thought was pretty big disappeared almost completely
- To my surprise, average POI went so much to the left that I went out of adjustment limits, had to re-set the rear sight
- Most importantly, with combination of everything my shots started to go all over the target. I expect main reasons are shared between not perfect focus on front sight and overcompensating (as even slight sight misalignment became too obvious)

Other than obvious "back to a dry firing on a white wall" where I am anyway now, what can be done? Increase the rear sight gap? Get the better adjustable iris? Forget about iris and accept a very blurry target?
brent375hh
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Location: Minneapolis

Re: Eyesight, sights and iris

Post by brent375hh »

If you ran out of rear sight adjustment, I think you are sneaking in the other eye image, or are severely snatching at the trigger assuming right handed. Have you tried shooting off of a rest, and really go for a surprise break?

I shoot with a Gehmann clip on iris and have sharp everything. It work best for me, but I really have to focus on the front sight intently. I also shoot with an old prescription pair of glasses that is ,25 diopter more positive than current.

When it comes to shooting vision, I have seen more setups than you can shake a stick at, especially in trap. They all seem to work for somebody.
Pat McCoy
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Re: Eyesight, sights and iris

Post by Pat McCoy »

Recheck your eye dominance. It can change, especially when their is a physical problem with one eye. It may be that brent375hh is correct, and you were looking with the best eye.
thirdwheel
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Location: England

Re: Eyesight, sights and iris

Post by thirdwheel »

Think you may have found you have answered your own question as you have found if you bring your target into focus by using an iris your shots go all over the place. What you want to do is to be able to see the molecular structure of the front sight - meaning it it perfectly in focus. That will mean the target is out of focus and that is exactly what you want as it stops you being drawn to it and not focusing on the front sight, the rear sights will be out of focus slightly this is again good as it makes the front sight stand out more. This total focus on the front sight throughout the shot process including the follow through controls everything and it is what is used by your subconscious mind to deliver the shot.
By the way, astigmatism is the defect caused by a slightly miss shaped cornea and this distorts an image out of shape eg a round circle to oval, this is corrected by your optician quite easily and is separate from the correction they make for your focal distance at different distances.
You will train your non dominate eye to do the job over time using the blinder, ever seen small children with a patch over a good eye, the optician is doing exactly what you are doing forcing a weaker eye to do some work and become used to working well.
The iris for shooting is not used to bring things into focus but to adjust for different light levels at different competition venues (it can reduce shadowing around the front sight for some) or to give tunnel vision to blank out distractions and in all instances the aperture is large and not narrowed down enough to effect focus.
I can hear the next question already - if I cannot see the target how can I hit it? - "Area aim" in the area below the now black fuzzy blob, "just do it" and follow through keeping a perfect alignment of the back and front sight.
Last edited by thirdwheel on Sat May 01, 2021 8:28 am, edited 2 times in total.
UnGe
Posts: 161
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Re: Eyesight, sights and iris

Post by UnGe »

brent375hh wrote: Tue Apr 27, 2021 8:13 pm If you ran out of rear sight adjustment, I think you are sneaking in the other eye image, or are severely snatching at the trigger assuming right handed. Have you tried shooting off of a rest, and really go for a surprise break?
I have a blinder on my left eye (a piece of scotch), so it should not have any impact. Snatching - maybe, this fits my over-compensation theory (desperate adjustments of hold have no chance not to impact the pull). I failed to do the experiment scientifically (removing only one variable), re-setting the sight and removing iris seem to help to keep shots close to the middle
UnGe
Posts: 161
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Re: Eyesight, sights and iris

Post by UnGe »

thirdwheel wrote: Wed Apr 28, 2021 8:33 am I can hear the next question already - if I cannot see the target how can I hit it? - "Area aim" in the area below the now black fuzzy blob, just do and follow through keeping a perfect alignment of the back and front sight.
Thank you! One problem that I see with the area aim is that it still assumes at least some clarity of the blob (with vertical fuzziness impacting more, as mind should do much better job in finding the middle of the blob than its edge). Let say that the distance to the front sight is 1m. It means that fuzziness of +- 1mm will result in +-10mm for POI. My rough estimation is that I see +-3mm, this is confirmed by the oval I see on the results (https://targettalk.org/viewtopic.php?f= ... 20#p307441). The oval is diagonal for other problems I am actively working on.

OTOH I think I am making a usual rookie mistake - chasing the problem of the lowest priority. I should address this one only after all of my shots fit this oval and it becomes vertical. Only after that one should start experimenting with lenses, irises and such
thirdwheel
Posts: 185
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Location: England

Re: Eyesight, sights and iris

Post by thirdwheel »

I could show you the maths for irregular alignment of the front and back sight and that is scary and you would wonder how it is possible to hit the ten, parallel misalignment is nothing in comparison. Psychologically beginners want to go for the middle of the black especially if they have come from rifle or plinking in the back garden. Don't fall into the trap of hunting out the edge of the black because if you do you will draw your focus away from the front sight and you are on the road to madness and inaccuracy. Get the perfect sight picture and set yourself up using your stance to place the sight picture in the lower half of the target way away from the black. It is called sub six and than means going low and taking a leap of faith that you can place the pistol in the same spot every time. Use the outer shape of the target as balance reference, yes the fuzzy black blob helps to get you there left and right but look at the front sight alone, and believe. Why does it work? Once you have trained your brain to put it there it will automatically place it there and you can focus on seeing that fantastic contrasted sight picture on the cream background and following through.
stephen_maly
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Re: Eyesight, sights and iris

Post by stephen_maly »

Probably the biggest problem to overcome is keeping the alignment of the front and rear sights. This requires just the right amount of gripping (not too tight or too loose). Too tight usually results in pivoting at the wrist and resulting in widely scattered shots. Just patiently practice dry firing by holding the pistol with the sights aligned and with your focus on the front sight. This will help you achieve a steady hold which is necessary for good grouping. Find someone who has some experience shooting air pistol to make sure the trigger blade is in the correct position for your hand (so that you are not pulling the gun out of alignment in the process of firing). Make sure the trigger travel has plenty of distance so that you are not hitting the frame at let-off before the pellet leaves the barrel. That has a way of scattering pellets also.
You might play some nice classical music in the background to make the training less of a chore.
'
UnGe
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Re: Eyesight, sights and iris

Post by UnGe »

Disclaimer for a focused help (pun intended): I am not new to shooting, I am just new to shooting with old eyes :)
Rover
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Re: Eyesight, sights and iris

Post by Rover »

Although you may THINK that your aiming eye is OK, you may still need correction for astigmatism. Just because your eye focuses on the front sight (a good thing), it doesn't mean that you don't need correction.

A quick and dirty way to tell is to look through a red dot sight. If the dot is clean and round (no oval or flaring), then you're probably OK.

The other posters are right: you don't need to have the bull anywhere near in focus.
atomicgale
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Re: Eyesight, sights and iris

Post by atomicgale »

thirdwheel wrote: Wed Apr 28, 2021 4:00 pm . . . you are on the road to madness and inaccuracy . . . .
Been there, done that.
UnGe
Posts: 161
Joined: Tue Mar 02, 2021 4:24 pm

Re: Eyesight, sights and iris

Post by UnGe »

Rover wrote: Thu Apr 29, 2021 8:05 am Although you may THINK that your aiming eye is OK, you may still need correction for astigmatism. Just because your eye focuses on the front sight (a good thing), it doesn't mean that you don't need correction.

A quick and dirty way to tell is to look through a red dot sight. If the dot is clean and round (no oval or flaring), then you're probably OK.
I fail this test. But I may need an optometrist that knows what is necessary. I've already got prescriptions for 1', 2', 3' and distance, for now playing with combination/approximation for a self-prescribed one (I wish there was a way to make this experimentation cheaper)

P.S. I actually found a cheaper way. I should stop ordering protective anti-fog ones, and first nail down optical parameters on cheapest possible simple ones

P.P.S. If somebody with similar problem can give an advise on how to re-combine prescriptions I already have the best way, it may help to narrow down.
brent375hh
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Location: Minneapolis

Re: Eyesight, sights and iris

Post by brent375hh »

If I was in your shoes, I would experiment with the gun on a sand bag. Then try everything one at a time until you find the best group size. Hopefully you can shoot close to 100, or at least keep all of your shots inside a quarter size group.
Once you figure out the best way to do that, then it's off to the races on being able to hold the gun and trigger the shot as best you can into the center.
UnGe
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Re: Eyesight, sights and iris

Post by UnGe »

UnGe wrote: Tue Apr 27, 2021 7:28 pm - To my surprise, average POI went so much to the left that I went out of adjustment limits, had to re-set the rear sight
Lesson learned - examine your hardware before coming with theories. I just discovered that the front sight was loose :(
So scratch this one. Fixed and re-tested, average horizontal POI is the same with or without iris.
B Lafferty
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Re: Eyesight, sights and iris

Post by B Lafferty »

FWIMBW, I had an optometrist measure from my eye to the front sight of my Benelli Kite and produce a prescription for my dominant left eye focusing on the front sight. I do have astigmatism and have been near-sighted all my life. I've tried using the lens focused on the front sight with only minimal success. It just seems to me that when focused on the front sight the target beyond is just too blurred to properly (consistently) place the front sight at sub-six for accurate shots.

I've gone back to shooting with my progressive lens glasses. My scores presently with the progressives run four to six points better per target shot than with the fixed focus lens. I do occasionally try shooting with the fixed focus lens, but my scores are consistently the same as previous times using that lens.
"No mud; no Lotus."-- Thich Nhat Hanh
brent375hh
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Re: Eyesight, sights and iris

Post by brent375hh »

B Lafferty wrote: Thu Apr 29, 2021 12:28 pm FWIMBW, I had an optometrist measure from my eye to the front sight of my Benelli Kite and produce a prescription for my dominant left eye focusing on the front sight. I do have astigmatism and have been near-sighted all my life. I've tried using the lens focused on the front sight with only minimal success. It just seems to me that when focused on the front sight the target beyond is just too blurred to properly (consistently) place the front sight at sub-six for accurate shots.

I've gone back to shooting with my progressive lens glasses. My scores presently with the progressives run four to six points better per target shot than with the fixed focus lens. I do occasionally try shooting with the fixed focus lens, but my scores are consistently the same as previous times using that lens.
Are you using the top of the glasses, or are you raising your head to a point into the progression of the "reader" section?
B Lafferty
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Re: Eyesight, sights and iris

Post by B Lafferty »

brent375hh wrote: Thu Apr 29, 2021 12:39 pm
B Lafferty wrote: Thu Apr 29, 2021 12:28 pm FWIMBW, I had an optometrist measure from my eye to the front sight of my Benelli Kite and produce a prescription for my dominant left eye focusing on the front sight. I do have astigmatism and have been near-sighted all my life. I've tried using the lens focused on the front sight with only minimal success. It just seems to me that when focused on the front sight the target beyond is just too blurred to properly (consistently) place the front sight at sub-six for accurate shots.

I've gone back to shooting with my progressive lens glasses. My scores presently with the progressives run four to six points better per target shot than with the fixed focus lens. I do occasionally try shooting with the fixed focus lens, but my scores are consistently the same as previous times using that lens.
Are you using the top of the glasses, or are you raising your head to a point into the progression of the "reader" section?
Good question. I'm probably looking through a point a bit above the mid-point of the lens. 55% to 60% up from the bottom of the lens.
"No mud; no Lotus."-- Thich Nhat Hanh
UnGe
Posts: 161
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Re: Eyesight, sights and iris

Post by UnGe »

B Lafferty wrote: Thu Apr 29, 2021 12:28 pm I've tried using the lens focused on the front sight with only minimal success. It just seems to me that when focused on the front sight the target beyond is just too blurred to properly (consistently) place the front sight at sub-six for accurate shots.
Exactly my point that got a good amount of pushback here :)
B Lafferty wrote: Thu Apr 29, 2021 12:28 pm I've gone back to shooting with my progressive lens glasses. My scores presently with the progressives run four to six points better per target shot than with the fixed focus lens. I do occasionally try shooting with the fixed focus lens, but my scores are consistently the same as previous times using that lens.
Interesting idea with progressive lens. Question: doesn't it force you to move your head while lowering gun to the position?
UnGe
Posts: 161
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Re: Eyesight, sights and iris

Post by UnGe »

B Lafferty wrote: Thu Apr 29, 2021 12:28 pm FWIMBW, I had an optometrist measure from my eye to the front sight of my Benelli Kite and produce a prescription for my dominant left eye focusing on the front sight
There is interesting piece in http://www.pilkguns.com/ch16-shtml/
I think I'll try my distance +0.5 too
brent375hh
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Re: Eyesight, sights and iris

Post by brent375hh »

I tried hard to use the sweet spot of my progressive lenses, but failed at it. My vision is -3.50 with a + 1.25 progressive. I have my best luck with an older pair of glasses that are straight -3.25 with a clip on iris from Gehmann. It makes sure I use the exact same part of the lens each time. It also sharpens my front sight image.
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