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Discussion Starter · #1 ·
Spent some time on an indoor range today with mixed to poor results. Haven't really done any shooting for several years. Initially tried using simple shooting glasses. My usual prescription has a little magnification for distance but I regularly drive and work looking over the top of the lenses or without the glasses. I found that this didn't work at all well for either rifle or pistol. And was problematic when needing to switch to close use to open combo lock or read box labels, etc., on the line where swapping glasses when others were shooting could be dangerous and against range rules to be w/o eye protection.

Swapped back off line to my progressive lens bifocals and covered them with larger safety lenses. My usual glasses don't have great coverage even though they are polycarbonate so while the range attendant said, they'd have been acceptable, I don't think so. Plus, really poor results from the head angles needed and no help at all with the M1a.

Checking at home, single vision "computer glasses" seemed to work well for the pistol and the rifle. Have a scheduled yearly exam this weekend but was also thinking of starting with a pair of the dioptric glasses from http://shop.shootingsight.com/Safety-Shooting-Glasses-Shooting-Glasses.htm

I've seen several sources for approaching this with shooter bifocals, etc., with the correction in the upper or upper center. At this time, I don't need pistol corrections in daily wear but might want to consider that if I go for a CCW.

So besides, the single vision shooting glasses mentioned above, is there anything in particular I should ask the optometrist to check, or distances to check, recommendations for corrections to go with bifocal shooting glasses with a small alternative location on at least the right/dominant eye?
 

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Eye Master
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The medical term for an increase of power to see closer is just "ADD".

Tell your doc you want to 'add' 0.75 for pistol/AR, or 'add' 0.50 for long rifles like the M14. Those represent the power needed to get to the hyperfocal distance of the front sight.

The safety shooting glasses I sell are ideal if you have good distance vision, and ONLY need help reading. If the doc says you need correction for distance, even a mild one, I recommend you go the path of making a pair of glasses with the 'add' values I recommended above. If you want to add bifocals for up close, fine. However get regular bifocals, not progressive or 'no-line', as it is difficult to get consistent focus on those.
 

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I have the same problem. While not a direct answer, I found that fiber optics help for daylight, and Tritium for indoors. On my target handguns, I have fiber optics, also on my levergun. My CCW weapons have Tritium.
 

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Rich,

The problem is not the visibility of the sight, it is that as you get old, the lenses in your eyes get hard and lose their adjustment range. When you were young, the lenses could just focus in close, now they cannot. So while a bright sight post can make you pay more attention to the sight, you have not really fixed the focus problem.

This is what lenses in reading glasses do. They can artificially shift your focal point closer to you, so you do not have to rely on the eye's non-functioning ability to shift focal point. The trick is simply figuring out how close you want your focal point. As lens power increases, your focal point gets closer. For reading, you want it at arm's length. For shooting, that's much too close, because you get a great front sight, but the target is blurry.

The correct distance to focus at (and what your eye used to do without you even thinking about it) ends up calculating to be the optical average of focusing perfectly on the target, and focusing perfectly on the sight. When you run the math, it ends up as an add of 0.5 or 0.75, depending on the sight radius of what you are shooting.
 

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OK Art, you have my attention..... Getting tired of trying to figure out which of the front post blurs to put on the blurry blob down range and my eye doctor doesn't seem to get the whole rifle setup.

My bifocal prescription is:
OD: SPH +2.00, CYL +075, Axis 170, Add +225
OS: SPH +2.00, CYL +025, Axis 175, Add +225

Based on what you said I am thinking of getting some dedicated shooting glasses without the progressive bifocal but with the regular bifocal insets. Am I correct in the assumption that we are talking about aiming through the regular part of the lens and only using the bifocal part for close work? Is the shift you are talking about something I can calculate based on my prescription or do I need to go back and try to explain it to my optometrist again?
 

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Yeah, it's that easy.

For long rifles, add +0.50 to the sphere, so your prescription would be
OD (right eye) SPH +2.50, CYL +0.75, Axis 170

For pistol or AR you add +0.75 for: SPH +2.75, CYL +0.75, Ax 170.

The indicated ADD is for the bifocal power. Diopters are the inverse of focal length (in meters), so an add of +2 to your distance vision will focus you at 1/2 meter, about 20". Your add of +2.25 will focus you at 1/2.25 meters or 0.44 meters, which is 17.5".

So on the prescription above you would tag on the phrase 'ADD' if you want a bifocal, and then put in a number that corresponds to where you want to focus. 2.25 is probably not bad. Do beware, we already added +0.50 to the top part of your lens, so to get the same reading power, you do not want to add another 2.25, but only +1.75 more.

Cheap glasses can be had on-line at Zenni Optical. They mail them from China. Top quality lenses as far as I can tell.

Your option what to do with the non-shooting eye. You could leave it as distance vision, or you could increment it by the same amount. If you are working with a custom glasses maker, you can likely fool around more easily. Commercial people will never have seen someone who wants one add power in one eye, and a different one in the other, so the ordering is not set up to handle it. Thus from Zenni I recommend you add the +0.50 to both sphere values, and then make the add +1.75 for both eyes.

Bottom line, for an M14 you would want the following:

OD: SPH +2.50, CYL +0.75, Axis 170, Add +1.75
OS: SPH +2.50, CYL +0.25, Axis 175, Add +1.75

With these you would aim through the top part of the lens, and the bifocal would be for writing in your log book.
 

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I have been using 0.5 power safety glasses for rifle and 0.75 glasses for precision handgun shooting. To have a set of bifocals made makes more sense, so I am able to see at distance out of my non-shooting eye.


If I understand this correctly, the lens used for the aiming eye is reversed? The reader portion is forward and the distance prescription is ground in the lower third of the lens?
 

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No, it is similar to a regular bifocal. Bottom lens is for close up work, however the top 'distance' lens has been modified to add a little power, either 0.5 or 0.75. This way the 'distance' lens becomes a shooting lens, and the bifocal for up close remains unchanged.
 

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Cheap glasses can be had on-line at Zenni Optical. They mail them from China. Top quality lenses as far as I can tell.
Prices and the lens quality is good. The frames are cheap and somewhat flimsy though. I have ordered a couple different pairs of shooting glasses from Zenni and overall have been satisfied with them.
 

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not to steal the post but what if you shoot optics?

I have these issues for sure
 

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Discussion Starter · #14 ·
What about getting a scope on a high Bassett mount, to get your head up a little, and be looking through the lens of your glasses?
My current bifocals lower section will correct adequately to see the sights, more or less, but it's in the lower third or so of the lens so it requires an odd tilt back of the head and looking downward. I can kind of accommodate a pistol that way but not a rifle.

Optics have a focusing eyepiece so I could adjust that adequately, probably even with or without glasses. My cameras have an adjustable diopter feature in their eyepiece finders so I get sharp view in the finders but as many my age, maybe need the glasses (lower portion) to see using the rear screen or to see button labels, etc. I can't use a rear screen device that doesn't have a separate eye finder without my glasses, my arms are too short!
 

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Discussion Starter · #15 ·
So, I should be able to get a regular prescription, set up for both distance and close-up for work, reading, etc., from my regular plan and optometrist and exam. Then if a "shooter's bifocal" or similar adjustment desired, in the upper center, etc., or just for a simple bifocal I'd add the diopter adjustment, deciding on either a rifle or pistol adjustment.

There seem to be some on line sources that handle these specialized placements either in glasses or the inserts for eyeshields, like ESS, Wiley and the like, and I'd guess (wonder?) that the ability to have a lower "reading" section and an upper slice for shooting, as well as regular distance vision is going to depend on lens size. They need pupillary distance as well as corrections?

A bit of a side question, will a lens/glasses with a distance diopter for shooting (and hyperfocal considerations) be suitable for general wear, driving, etc. I'd think not but?
 

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not to steal the post but what if you shoot optics?

I have these issues for sure
By screwing the eyepiece in/out you are effectively adjusting the sphere value of the eyepiece. So if you DO NOT have an astigmatism, you will simply dial in the scope.

If you DO have an astigmatism, you can correct it one of several ways: you can put the correcting lens in eyeglasses. It works, but you are subject to fogging, and when you shoot prone, and look diagonally through the extreme upper inside corner of your lens, you get some distortion. THe better way is to take the lens you need and simply fix it inside a scope cap, then put on the scope cap to hold the lens on the end of your scope.

Down side is that the lens needs to be oriented, and typically the eyepiece is what rotates to adjust sphere value, so there will be some futzing to get the eyepiece screwed right and not lose orientation of the lens. But it can be done. One person who agreed to try this when I first had the idea just won the civilian trophy at Camp Perry, so it does work.
 

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Discussion Starter · #17 ·
A polarizing filter for a camera lens has a threaded ring for mounting to the lens with an attached rotating ring that holds the filter allowing for it to be rotated to the desired position for angle to the sun or if the lens front rotates when focused, etc. Popping out the polarizer and inserting the correcting filter might allow you to rotate the correcting filter to a desired orientation more easily. Not sure how easy that might be to attach it to the eyepiece or if sizes are similar enough.
 

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Yes, thanks, and I started looking at that. Trouble is that a lot of scopes have a rubber ring attached to the eyepiece, so the internal threads are not accessible. The other issue is that there is no standard thread size, so I'd need to develop scope adaptors for a bunch of different models. I'm still thinking how to fix this.
 

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Discussion Starter · #19 ·
I was just thinking of it as a convenient place to start. I don't know but would think most scopes aren't threaded on the eyepiece end, just that you might find a close enough fit and still have the rotating section.
 

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No, it is similar to a regular bifocal. Bottom lens is for close up work, however the top 'distance' lens has been modified to add a little power, either 0.5 or 0.75. This way the 'distance' lens becomes a shooting lens, and the bifocal for up close remains unchanged.
If I want to use the rear sight inserts you sell are you saying to use .5- .75 or isn't it relevant to your reading glasses.?

I pretty much still have perfect distance vision, thank you LASIK; however I use 2.5 reading glasses. Does that change the power recommendation?
 
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