TargetTalk

My recient experience has shown how important concentration on the foresight is. I’m now looking at how I can improve my ability to do this, one way (in addition to training & practice) is the use of glasses.
My understanding (please correct me where necessary);
Ideal; that rested eye focus point should be on the foresight. Normally this will give a well focused overall sight picture but will result in the target being indistinct. The compromise; to have the rested focus point somewhere close to but beyond the foresight such that the target is distinguishable, but fuzzy. The amount the focus point will be past the foresight, will depend on the individual & the distance to target.

From my reading for a ‘normal’ eye which does not require correction, the prescription to achieve above will usually be between +0.25 and +0.75, and needs to be determined by trial & error or with the help of gun ‘friendly’ optician. Choosing the highest + value which gives an acceptable compromise. For AP +0.5 seems to be norm?

My last eye exam results were for corrective lens with prescription -0.75 cyl (eye is natural +0.75). If I am correct this would mean my potential lenses for pistol shooting would be between -0.5 and none required i.e. zero.

Assuming I can find optician who will allow me to bring pistol to office. For AP would the distances available in optician’s office be sufficient for selecting a lens which will give reasonable clarity on 10m target (don't recall there being anything like 20ft in the small exam room)?
Would any regular optician have the equipment required to select the best lens?

Are coloured filters required for indoor AP range use, if so what is criteria for selection?

My next step is to find the ‘friendly’ optician, I use Specsavers for normal glasses, not sure though if they will facilitate as in 'Dr. Wong's guide for eyecare professional'.

"Assuming I can find optician who will allow me to bring pistol to office..."

Not wanting to alarm anyone, I fabricated a wooden "gun" for just this reason. I glued together a 5" and 10" piece of 1"x2" at a right angle, to give me the grip and bbl.
I fabricated a front sight by filing a steel wood screw flat to about 1/8" wide, and screwing it into the front of the "barrel", and a back sight by cutting a 3/4" length of 1" x 1" angle iron, cutting down one of the 1" sides to 1/4", filing a notch in it, drilling two holes and screwing it to the back of the "barrel".
I painted the sights black, and meant to paint the "gun" fluorescent red or green, but never got around to it.
I took it into a pharmacy and after showing it to the pharmacist, and explaining my intentions, I tried out the "off the rack" reading glasses, to get the + diopter I needed.

This was back when I needed several strengths due to changing eyesight caused by diabetes. I'd often have to change glasses during a match, using a clip-on occluder and iris diaphragm. I've since, learned to control this, and use Champion shooting glasses, with a +1.00 lens, and no iris.

Paul

Just a slight correction/observation/socratic question- why do you think you need to compromise between focus on the front sight *and* the target? What useful information does the target provide?

No, really- why do you need "focus" on the target at all?

Steve Swartz

Steve is totally correct. The target is the only thing that dosen't move. Its only function is to catch the bullet so it can be scored. You need absolutely perfect focus on the front sighe and enough depth of focus to see the rear sight clearly so ypu can be sure of sight allignment. As to color lens, I never used them because they decrease the intensity of light striking the shooting eye causing the pupil to dialate and decreasing the depth of focus. I hope this is helpful. Good Shooting Bill Horton

If you are in San Francisco, see Dr. Norman Wong. He is a Bullseye shooter as well as a top-notch eye guy.

After my normal exam and with a preliminary prescription ready, we went to his front office where he handed me a broom handle with a red dot and the rib from a 1911 screwed onto a platform affixed at the appropriate angle. He put a pair of adjustable glasses on my face preset to the trial prescription and we spent the next half hour fine-tuning the prescription aiming out the front of his store at a target sized shape about 50 yards away on the building across the street.

I left with several prescriptions that day including one for my normal walk-about progressives and another for a custom lense for olympic-style shooting frames for shooting iron sights, and I also know exactly what strength I need to add to my street glasses for iron sights if I choose not to buy the olympic-style shooting frames.

It was the best eye exam and Rx I've ever had, and the gentleman *knows* what shooters need.

Oh yeah, at a Bullseye match later in the week in Sunnyvale, he let me shoot his Masaki 1911, too, but I don't think that's normally included with the eye exam.

I should have mentioned in my reply post to Guest, that he need not worry about the distance to the eye chart, in fact doesn't need an eye chart at all, just a pistol (or replica), with sights to focus on. That's why all I needed was a reading glass display to give me all the info required. A few shots at the blank back side of a target is all anyone needs to convince them not to focus on the target!
Paul

I currently shoot more than the 50M "limit" for this forum, but had been using a prescription for my glasses so that the front sight of my service rifle was in-focus while the target (100 to 600 yards) was fuzzy. One day, I tried shooting with my regular distance glasses -- the front sight was fuzzy but the target was clear. My scores were dramatically better. I now wish that I had simply tried this for 10M shooting, too.

Hence, I suggest that rather than accept the "common wisdom" that the front sight must be in-focus, that each person try various approaches from the target to mid-target to the front sight being in-focus. While I agree that mental focus on the front sight is vital, optical focus is not (for some people).

The lucky ISSF rifle shooters can have the best of both worlds with a + diopter at the rear sight and a - at the front. Not allowed in NRA shooting, unfortunately.

jrmcdaniel wrote:The lucky ISSF rifle shooters can have the best of both worlds with a + diopter at the rear sight and a - at the front.

Can they? Wouldn't that be covered by rule 7.4.2.3.1 "Correcting lenses and telescopes must not be attached to the rifle."

jrmcdaniel wrote:One day, I tried shooting with my regular distance glasses -- the front sight was fuzzy but the target was clear. My scores were dramatically better. I now wish that I had simply tried this for 10M shooting, too.

Hence, I suggest that rather than accept the "common wisdom" that the front sight must be in-focus, that each person try various approaches from the target to mid-target to the front sight being in-focus. While I agree that mental focus on the front sight is vital, optical focus is not (for some people).

One good score does not equal a proven hypothesis. It's probably due to random variability or more likely the phenomenen where doing something different makes you concentrate harder. By all means try different techniques but don't shy away from concensus opinions, they've been arrived at for a reason, namely they work !

Rob.

Since there are lens inserts for the front and rear sights, I assume this must be legal for some shooting. It would not be a telescope, per se, since the usual lenses are a + in the rear and a - in the front which would produce a sleightly smaller than normal image (a telescope would have a - in the rear and a + in the front for a Gallileo scope).

Also, my results were not from one match. Keeping an open mind is more important than almost any amount of "common knowledge" IMHO. What works for you is far more important than being (politically?) correct. If you do not try alternate approaches, you will never find out if they work better for you.

jrmcdaniel wrote:Since there are lens inserts for the front and rear sights, I assume this must be legal for some shooting.

Not for ISSF shooting AFAIK.

I know that several sight manufacturers make models with adjustable diopters but am pretty sure you cannot use them in ISSF matches. I believe they can be used for our domestic (NSRA rules) smallbore rifle matches here in the UK.

+.75 is actually my preference. I still see the target too clearly with only +.5

David Levene wrote:

jrmcdaniel wrote:The lucky ISSF rifle shooters can have the best of both worlds with a + diopter at the rear sight and a - at the front.

Can they? Wouldn't that be covered by rule 7.4.2.3.1 "Correcting lenses and telescopes must not be attached to the rifle."

As I am not a rifle shooter I do not know for sure but I have a feeling that I have heard about a change 2008. A correcting lens is allowed in the diopter. I leave it to David to inverstigate though.

Kent

Reinhamre wrote:As I am not a rifle shooter I do not know for sure but I have a feeling that I have heard about a change 2008. A correcting lens is allowed in the diopter. I leave it to David to inverstigate though.

I'd be surprised and would expect such a major change to be from January 2009 (if it happens). Not impossible though.

When I posted the question thought I was logged in, but obviously was not, so Author showed as Guest.
Thanks All, for the responses, sounds like the prescription should be solely to give perfect focus at the foresight.
Dr. Wong in his ‘guide for eyecare professional' does mention having more than 20 feet during selection is preferable, but maybe this is just not required for the shorter AP 10m target distance.
Hopefully I won’t have to go to the lengths Paul did to get an exam.
And coloured lens are not recommended.

Joe.

Joe, I'll second what Paul says about checking out off the hook reading glasses. It will be the cheapest way of experimenting and if you then find you need "real" shooting glasses, you will know what to order. If you find you need to go down to .25 diopters as opposed to the standard .5 diopter variations in ready to use readers, you can get lenses made to the pattern of your RTU for around £10 from internet suppliers. I think mine were from http://www.specsfactor.co.uk/ (but I've mislaid the paperwork) but if not them, a couple of phone calls to internet outfits will find you someone.

Hi all

I have a similar prescription to one of the previous posters (-0.75) with an astigmatism correction of -0.75 30. So if I was to try some cheepo specs (£10.50 !) would I keep the same astigmatic number and try a -0.25, -0.75, 30? I have tried without specs but cant get the foresight in focus, it seems to be focussing too far back - the rear sight is crystal!!

thanks for any help in advance.

cheers

Ed

Problems with astigmatism can be managed with adjustable iris.

If you don't have one, try making small holes of various sizes on a piece of electrical tape and attaching it to your glasses and see if it makes things better.

AAlex wrote:Problems with astigmatism can be managed with adjustable iris.

Not sure I agree with that - sure it will have the affect of putting everything in focus, but that's not the objective. If you want to get the best focus on the foresight then you need glasses that accomodate your specific astigmatism.

Rob.

I've been trying to think it through and work out what is going on with a shooting glass lens - not something I've ever thought about before ! It seems to me that the astigmatism correction has to be worth having. Then its just a case of getting the focus point in the right place.

Am I right in thinking that the focus points should be in the following order with the noted glasses prescriptions ? Obviously I'm not sure of the exact place....

My Eye Rear Sight 0.0 -0.25 ForeSight -0.5 Further away -0.75 Target

cheers

Ed