TargetTalk

So I got my prescription today. I wonder if I can use the same prescription for the shooting glasses (MEC). I use my left eye. Or do I have to find Dr. Norman in SF? My local optometrist actually knows something about shooting glasses. Her husband is into firearms, and hence when she was still under training she also studied a little bit on shooting glasses. Apparently shooting glasses prescription is an optional (no pun intended) study.
My AR has a diopter that pretty much covers everything there is..including anti-astigmatism. So I wonder in that case all I need is my normal prescription for the MEC glasses? She can order the lens for me.
If not that means I have to see Dr Norman and have both eyes tested with him.

Vince,

normally you want a different prescription for rifle shooting to your general distance. Because your aim is much more stable than for pistol, focus is on the foresight, or rather a few feet ahead of it. +0.50 dioptres (over your distance prescription) is commonly mentioned as being about right for rifle. It's quite right that not everyone needs a prescription for shooting, but a lens removes the need to consciously think about where your focus is, you just look and it's there.

By dioptre on your rifle, do you mean the rearsight aperture, or an adjustable Gehmann/Centra 1.5X lens? Neither will do anything for astigmatism. Only a prescription lens that is set for the individual cylindrical correction will counter astigmatism. The rearsight aperture, due to its size, narrows and elongates your focus so you can see the foresight clearly, and the target reasonably clearly. The 1.5X adjustable lens makes the sight picture larger (by 1.5X) and allows you to alter the focus.

My diopter has everything: iris, 48 color filters, more light or less light, and then anti-stagmatism. If I have my left eye lens having a prescription, then does that mean when I aim I would aim exactly the same as someone who does not need glasses?

Pistol I know I have to be examined different.

Vince,

unless your dioptre was custom made for you after you had sent your prescription to the manufacturer, then it won't correct for astigmatism. NO dioptre does this; colour filters yes, polarised filters yes, adjustable aperture yes (more/less light), 1.5X larger yes, adjustable focus yes, astigmatism no. To correct for astigmatism the lens must be specially ground for your individual prescription.

For the second question, yes. Once your vision is corrected with a lens, then you would not be at a disadvantage to someone with good vision who does not need glasses.

579 Cylindrical lens system, 0-2% Sphere

Until now shooters suffering from astigmatism have been obliged to use shooter's spectacle
frames with their inability to adapt to constant changes in eyesight whether it be day to day
or even hour by hour. Subsequently large number of shooters stop shooting as a result due to
poor scores and frustration - but not any more.
Opthalmic examination will accurately measure and diagnose your symptoms giving an
opportunity to do something about them. If you suffer from the common problems of myopia
(short-sightedness), hypermetropia (long-sightedness) or astigmatism - we can cure them all
with the use of 570-579 as an example (see page 15).
The device is a combination of optical correction for both axis and astigmatic problems. Axis is
set against the rim markings 0 - 180° then locked in place with three allen screws. Sphere is set
by use of the two levers which are used in matched but opposing movements for day to day
eyesight needs. Depending on levels of eye fatigue, sugar levels etc., your eye sight can change,
but with a simple click of the levers, perfect focus can be obtained once again.
We offer two options: 579 0 - 2% (involves 90% of sufferers statistically)
579-4 0 - 4% (involves 2 - 6% of sufferers statistically)
To fit either is extremely simple but requires partial dismantling of your iris using the U-spanner
originally supplied. A replacement can be ordered if needed. Fitting requires one of our
adaptors so please look at the list of our products together with the illustrations below. The
adaptor slides inside 579`s body and locked into place with three small allen screws. Each
adaptor is internally threaded to allow the 579 to be fitted on your iris. This is done using
your existing irises front thread - except 500, 501MC, 510 and 510-S which require 577 due
to construction method. If attaching to a straightforward iris (as 550) there is nothing to do -
however if you wish greater sight correction then 50309 (black) or 50300MC (silver) diopter is
required. Fitting to our unit with existing diopter, procedure is straightforward as described
above. Assembly and user manual are included.

Video tutorial how to assamble and adjust a Gehmann CLS

Vince,

mea culpa, I hadn't noticed this product before. If you have this, you don't need a shooting lens; as described in your post, this gadget replaces glasses. What a shooting lens does is focus your eye to a set distance, and correct any astigmatism, exactly what the Gehmann product claims to do, but is adjustable not fixed like a lens. Personally I won't be buying one. A lens would be much less complicated, cheaper, and much more sturdy; I'd be worried about those levers being knocked out of alignment. It's also very long, so the rearsight has to go a long way forwards.

Tim S wrote:If you have this, you don't need a shooting lens; as described in your post, this gadget replaces glasses.

Unless, of course, you are shooting under ISSF (and possibly other) rules in which case it would be banned.

Conradin, let us know the make of the 570 - 579 devices.

Thankyou.

BR1942 wrote:Conradin, let us know the make of the 570 - 579 devices.

In case he doesn't answer, it's Gehmann.

BR1942 wrote:Conradin, let us know the make of the 570 - 579 devices.

Thankyou.

Um, it is Gehmann, I bought the diopter for my winzeler armbrust originally.

David Levene wrote:

Tim S wrote:If you have this, you don't need a shooting lens; as described in your post, this gadget replaces glasses.

Unless, of course, you are shooting under ISSF (and possibly other) rules in which case it would be banned.

I feel it should be legal, otherwise Gehmann would not make it. Perhaps you can point out which rule disallow anti-stigmatism item.

Unfortunately for ISSF no lenses fitted to the Rifle you must wear them as glasses. Someone may be able to find the rule for you or you can look it up online. This is for ISSF not your local rules.

7.4.1.6(a) Corrective lenses and telescopes must not be attached to the rifle;

Tim I am not an eye dr. but I should have been . With the problems I have had with my eyes I would have saved money over the years. One thing I disagree with in your post is trying to focus your eye between the front sight and the target. This was certainly the thinking some years ago. However the current thinking is that it is not possible to focus the eye on "nothing". Your eye has to focus on an object, so that means while a shooter might think he is focused between, he is actually changing focus rapidly between the sight and the target.

As to astigmatism the only true way to fix that for shooters is with old style hard contact lenses which actually change the shape of the eye to correct the astigmatism. It was certainly the best fix I ever found. Took my eyes from 20- 600 without glasses to 20-12 with no astigmatism.

Rifle attached lenses are only legal in American conventional rifle. Issf and I think the rest of the world outlaw attached lenses on rifles.

GWSB could you explain a bit more on point of focus I would love to hear how and where you set your focus, I have always thought there had to be "balance" somewhere there?

Art (ShootingSight) could probably explain this better than me but...

The idea (as I understand it) is that you want to be focused at a point twice the distance from the foresight - this is called the hyperfocal distance. At that point objects at half the hyperfocal distance are equally in/out of focus with objects at infinity (like the target).
Now, a +0.5 lens would bring your point of focus from infinity down to 2m - which is pretty much double the distance from you eye to the foresight. So by relaxing your gaze as if focusing on the target, you are naturally focusing at the optimal distance where the foresight and target are equally in focus.

One additional upside to this seems to be that you don't need to close the rear iris down so much in order to get the depth of field - as you would without the lens. For us older folks with our older eyes, there may be an advantage to a larger rear aperture... but that's another matter.

Lenses attached to the rifle are legal under NSRA rules here in the UK unless you also use an Eagle Eye.

K.

KennyB wrote:Art (ShootingSight) Lenses attached to the rifle are legal under NSRA rules here in the UK unless you also use an Eagle Eye.

K.

Ken,

I think you can use a fixed lens on the rifle with an eagle eye, but not an adjustable lens.

Gwsb,

I'm going on the explanation of my Opthalmologist, himself a successful smallbore shooter. My shooting lens is +0.50 over my regular glasses. The result is much more natural and comfdortable sight picture than without and consciously focussing on the foresight itself.