How blurry can you go?

[charliemow13]

I've just picked up my new glasses, a pair of readers, and with the new prescription the foresight is now very crisp and clear as is the rearsight. I think both eyes are now +1.5. The target is considerably more blurry than using my previous prescription. Didn't seem to affect my shooting, things just look a bit different and I'm sure after a few weeks it'll seem quite normal.

Is that pretty much the way it goes through your shooting career, eyes age, prescription changes, sight picture at the pistol end stays pretty constant but the target seems ever more blurry? And does there come a point where it's no longer possible to get a consistent point of aim? And words of wisdom from your learned folks would be much appreciated.

[Gwhite]

I occasionally have to test fire pistols for the team I help coach, and in the past, I didn't have any shooting glasses at the range. If you work at it, you can just line up the blurs, concentrating on the front blur (sight), squeeze the trigger, and still shoot just fine.

+1.5D is definitely more correction than I've heard anyone using, but as long as you can focus on the front sight and keep them lined up, I don't think there is anything fundamentally wrong with it.

[Ramon OP]

Yes, front sight as crisp as possible, target gets more blurry as prescription goes up. As age goes up the eye has more trouble and the prescription for short sightedness goes up. My shooting glasses have a slightly different prescription, as the front sight is farther than a book or the computer screen.

[charliemow13]

Thanks for the replies. I think the new prescription means I actually have the rearsight in clearer focus than the foresight.

The old prescription still works ok for me so I'll stick with that for shooting for now and start searching round for an optician who's familiar with needs of target shooters.

[Agt. Smith]

With my regular Rx (distance) I seem to be able to get a good image with the front sight in focus, and the rear sight and bull slightly fuzzy.

I made the mistake of trying an iris - stopped down pretty small (probably 1-2mm, somewhere between f/16 and f/22 I suspect). Wow. I recommend everyone at least try one.

I don't know if I could ever actually wear one all the time (heavy, no peripheral vision, goofy looking, etc.) - but the increased depth of field was remarkable.

The front and rear sights, and the bull, were all in focus (with my regular Rx anyway).

Good luck!

[thirdwheel]

You don't want to see the target black sharp as it pulls you away from the front sight, so this is why it is best not to use an iris, but if you do use the iris
use it with a large aperture to cut down peripheral distractions.
Correct picture is fuzzy target, crystal clear front sight and rear sight just going out of focus, rule of thumb is +0.75 D on distance but as you know all thumbs are different so my shooting lens is +1 D.

[Gwhite]

I use +1.25D, but with an iris. I think I need to go that high because of my contact lens prescription. I adjust the iris down so the sights are in focus, but target is still blurry. I find that my eyes tire over the course of a match, and an adjustable iris allows me to fine tune things as my vision degrades.

[charliemow13]

Thanks for all for input. It made me think i must be missing something as I didnt think my eyes are really that bad. So I had another eye test this morning with a local optician, one who was happy to spend a bit of time finding out what I was looking for and explaining the differences in the prescription to me, and did a few checks with me in shooting position, arm outstretched, so he could check which +D lenses worked best for me. Quite a different experience to my usual visit to specsavers. Turns out the old glasses I've been using quite successfully for shooting are +1.25D and the new readers I've got, while giving a really clear view on the front / rear sight, are +2.50D (+1.25D and then ADD +1.25, so +2.5D, as they are intended purely for reading). He suggested I could try a lense +1.50D for shooting but if I was happy with the +1.25D they would work just fine with my eyes as they are for now. No wonder the target was well blurred with the new glasses. Feel like I'm a bit more educated now, but still a ways to go to being wise!

[Gwhite]

Vision for pistol shooting is a very personal thing, and if you are particular, you can discern differences down to ~ 1/8D. This can be frustrating, because for normal lenses, the optical shops consider +/- 1/4D to be "good enough".

I've borrowed my old optician's lensometer, and measured a bunch of my lenses. Lenses specifically for shooting glasses tend to be fairly accurate, but I've found a few that were off a bit. You can set up your own measurement, but without a super bright light source, you can only measure the focal length of the entire lens. You will really only be using the middle, so you want to measure using an aperture. That cuts the light down, and the image becomes dim & hard to discern the focal length accurately.

Focal length isn't everything either. Depending on the light levels (which affects your pupil size), and/or an aperture, the "depth of field" will vary. This is the range of distances over which everything is in focus. I like to have my front sight sharp, and my rear sight somewhat in focus, which can be achieved with enough light or an aperture. Because light levels in ranges varies, I use an adjustable aperture so I can tune things.

Modern ranges tend to have pretty good lighting, which helps. A lot of older indoor ranges had very dim lighting at the firing line, which made it really hard to focus on the sights they way I like to.

[thirdwheel]

After pulling my hair out for some years over my shooting lens and after coming across the writings of Don Nygord I went down his route and bought a complete set of opticians trial lenses, trial frames and a second hand lensometer and now sort out my own shooting lenses and just get glasses made from an on line supplier with a plain lens in the non shooting eye.
This also allows me to take my funky florescent trial frames and a selection of trial lenses in my shooting kit to different shooting venues and if my normal lens does not cut it due to light conditions I can use the trial frames and adjust the vision with the trial lenses. It also has the effect of putting off my competitors as they are so impressed with my glow in the dark frames. Someone called them "steam punk" frames - whatever that is!
The lensometer showed up my old shooting lenses to be quite inaccurate, so thanks Don you were right!

[McMadCow]

I was just handed my first eyeglass prescription so all of this is new to me- some help would be greatly appreciated here. I've noticed a change in my eyes over the last year so I went from safety glasses with a blinder to a set of shooting frames with blinder, 42mm lens, and iris. I started with a +1 lens insert in there, but my focus is too far behind the front sight. I need to stop down my iris to get a sharp front post, which has obvious other problems.

So after I went to my eye doctor a couple of weeks ago, he gave me a prescription and also gave me some pointers on choosing a lens for my shooting frames. The problem is, the ones he said should work- don't. The +.50 and .75 both also produce a sharp focus back by my hand and not the front sight, and once again I need to stop down my aperture. Quite honestly, the original +1 actually works better that either of the lenses that closer match my prescription. These lenses are made by Champion for their shooting frames, I find it hard to believe that their focusing distance would be so wrong yet here I am.

So my questions are:
-Does anyone else have experience with shooting frame lens inserts giving you a bad focusing distance, and could you do anything (besides iris) to correct it?

-Failing that, is there anywhere online that will manufacture a single round lens for shooting frames based on your prescription?

I'm in the Bay Area, CA, so there's no good resources around here for this sort of thing. My eye doctor had literally never even seen a pair of shooting frames before and I had to explain to him how I needed them to work. I'm sure he gave me what he thought was the correct recommendation but somehow it's not working for me as it should.

[Gwhite]

It's a bit hard to say what's going on, but I suspect your new lenses aren't very accurate, and you are chasing errors in the lenses. Standard opticians consider +/- 1/4 diopter to be "close enough".

I would contact Art Neergaard at Shooting Sight. He can make custom lenses for you: https://shootingsight.com/product-category/lenses/

[eugene]

What I did was bought a prescription testing frame, a set of dioptre testing inserts at that well known Chinese site. Cost a small fraction of "real" shooting frame alone. Works fine for shooting even if you look a bit dorky.

[McMadCow]

Thanks guys! I appreciate the insight. I'm going to get a lens insert made for my prescription and hopefully that works out.

[David M]

Reading these posts, it appears that a lot of shooters are missing a major point about focus.
They are all talking about a + diopter lens to de-focus of +0.5 to +1 which is correct.
But it must be applied to your own distance focus script.
If by testing your eyes have a distance script of +0.75 with astigmatism of -0.25 at 120 deg,
then to de-focus you will need +1.25/-0.25 up to +1.75/-0.25.
So not all people will use a simple lens.
Find a friendly eye doctor, take along a copy of Dr Wongs article and have a eye test.
https://starreloaders.com/edhall/nwongarts.html

[Rover]

Thanks guys! I appreciate the insight. I'm going to get a lens insert made for my prescription and hopefully that works out.

Be sure to have them notch the lens so that you know the correct orientation. Having it in backwards sucks.

[McMadCow]

Be sure to have them notch the lens so that you know the correct orientation. Having it in backwards sucks.

I'm traveling in a free state for the holidays and I ended up getting my prescription filled at a local optometrist. He was kind enough to also grind a lens for my shooting frames. He mentioned leaving an orientation mark, and I'll probably actually have him check out the results in person. Everything should be done in a couple of days.

[PirateJohn]

My lens has a very visible notch right where the frame joins together. I suspect the lens will last me a couple of years.

[Gwhite]

The orientation notch is for your astigmatism. With round lenses, you can actually fine tune things a bit yourself. There are a variety of astigmatism tests patterns on-line that you can print out. You rotate the lens until everything is sharp & symmetrical.

https://commons.wikimedia.org/wiki/File ... tarJMW.pdf

[McMadCow]

The orientation notch is for your astigmatism. With round lenses, you can actually fine tune things a bit yourself. There are a variety of astigmatism tests patterns on-line that you can print out. You rotate the lens until everything is sharp & symmetrical.

https://commons.wikimedia.org/wiki/File ... tarJMW.pdf

Thanks for that! I do have astigmatism, so that comes in very handy. I was under the impression that I would be oriented one specific way, but it's good to hear that's all tunable.