Take a few minutes to explain shooting glasses?

[David W. Johnson]

I shot 3 position air in high school and then 3 position small bore and standing air with my daughter a few years ago. I've dabbled in 10m air pistol and lately am going back to it for something to do in the winter and because my current assignment is Belgium and they hate guns.

At 46, my eyesight isn't what it once was. I'm using reading glasses pretty much always. I have to use them to shoot so the sights are in focus. The target isn't quite as crisp as it once was, though.

I'm looking at shooting glasses. The purpose of the blinder is easy. What do the irises do for you? Can I use a corrective lens on the glasses to replace my reading glasses? If you really want, you can explain to me what the color filters do as well.

Sorry. Search on the internet failed to yield a 'shooting glasses for dummies' tutorial.

Many thanks!

David

[dronning]

The iris when reduced in size increases your Depth of Field (DOF) which is the distance in front of and behind that subject which appears to be in focus. The tradeoff is the smaller the size the less light you have and you do not necessarily want the target in crisp focus.

Filters - here is a link I used to figure out when I should use what lens color: http://www.morganoptical.net/lens_color

All you wanted to know about eyesight and shooting
(Dr. Norman Wong Articles as posted to the Bullseye List)
http://www.starreloaders.com/edhall/nwongarts.html

-Dave

[David W. Johnson]

Thanks for the links!

So, the iris helps you to focus on front and rear sights at the same time?

[dronning]

With the iris "stopped down far enough the rear sight, front sight and target will be in focus or clear. Just like in photography when you reduce the f-stop (iris) more of your subject will be in focus and the smallest f-stop will get produce a photo in focus "from near to infinity", if you have enough light.

In shooting that is not necessarily a good thing because it can more of a distraction for some people and can take your eye away from the front sight. Your need to find the balance that works for you.

I got rid of my iris for bullseye and went to prescription shooting glasses. I have one for dots and one for iron sights. I do still use an iris indoors with air pistols.

On overcast or dark situations you may not be able to use an iris at all.

-Dave

[David W. Johnson]

Thanks, Dave. Makes sense. When I don't have my glasses with me, I make a small aperture with my fingers and peer through it to read things. Looks silly, but it works. Not sure where I learned that.

I guess I'll invest in some really expensive eyewear that will never be seen off the range.

[FredB]

Thanks, Dave. Makes sense. When I don't have my glasses with me, I make a small aperture with my fingers and peer through it to read things. Looks silly, but it works. Not sure where I learned that.

I guess I'll invest in some really expensive eyewear that will never be seen off the range.

Another alternative would be to have your optometrist, with the help of Dr. Wong's writings, determine your desired prescription, and then have it made up in regular glasses at one of the super-cheap on-line glasses vendors. The result won't be as adjustable as the Olympics or Knoblochs, but it will cost a fraction as much, and will give you better eye protection as a bonus.

This solution won't easily permit the use of an iris and filters, but there are ways of arranging those things. In my experience an iris and filters are mostly distractions when pistol shooting - YMMV.

FredB

[ShootingSight]

Do a search on my posts on this forum. I'm not a doctor, but an engineer with some education in optics, and some experience as a photographer and a shooter. I've developed and sell glasses exactly for shooters.

Bottom line is that the optical balance which sharpens the sights, without giving up too much focus on the target is by adding +0.75 to your distance prescription for pistol or AR rifle, and +0.50 for a longer rifle. This will focus you at what is known as the hyperfocal distance of the sight.

If you don't wear glasses for distance, you just want those lenses.

Reading glasses are too strong, and typically start at +1.25 which brings your relaxed focal point so close that the front sight is excellent, but the target is too blurry.

[paw080]

Hi David, you said:

"At 46, my eyesight isn't what it once was. I'm using reading glasses pretty much always.
I have to use them to shoot so the sights are in focus. The target isn't quite as crisp as it once was, though."


When you are really focusing on the front sight, and it is a sharp image,

the target had better be a fuzzy blob. You have many choices of how you

hold the pistol in alignment relative to the target. But, this is not rifle shooting.

You can hold the aligned sights on center mass, six o'clock or sub-six; it's

your choice. Like the other responders, I say get thee to an Optometrist:

and stop trying to focus on the black bull.

Best of Luck; (did you say 46 years old? - you're still a baby!)

Tony

[Spencer]

The purpose of the blinder is easy.

to keep the light levels reaching both eyes equivalent, use translucent material rather than opaque.

What do the irises do for you?

not much, other than keeping your eye 'centred' - and only then when properly positioned.

Can I use a corrective lens on the glasses to replace my reading glasses?

You can, but it is the hard way of doing things

Can I use a corrective lens on the glasses to replace my reading glasses? If you really want, you can explain to me what the color filters do as well.

with the right color and saturation (for you, and the light conditions) can increase contrast and/or reduce eye-strain in very bright sunlight.

Shooting frames have the advantage of enabling the lens to be positioned so that you are sighting with the lens centred and perpendicular to your line of sight - this is unlikely with 'normal' spectacles.

[David W. Johnson]

Thanks for the responses, guys.

Excellent reading provided early on. I'm still working through the things written the the OD.

To answer a couple of comments: I hold bottom dead center. I'm used to the bull being fuzzy, it just seems more fuzzy now than when I was younger. I'm going to try an aperture to extend my depth of field. I think I'll be ok with my reading glasses with an aperture and blinder when shooting pistol, but may have to get shooting glasses for rifle due to a different angle of my head.

Thanks again!

David

[Rover]

The purpose of the aperture is NOT to increase the depth of field, but to have a uniform portion of the pupil in all lighting conditions.

The aperture WILL increase the sharpness of the bull, but wait until you get correct glasses before doing/spending anything else.

[EdStevens]

Bottom line is that the optical balance which sharpens the sights, without giving up too much focus on the target is by adding +0.75 to your distance prescription for pistol or AR rifle, and +0.50 for a longer rifle. This will focus you at what is known as the hyperfocal distance of the sight.

If you don't wear glasses for distance, you just want those lenses.

Reading glasses are too strong, and typically start at +1.25 which brings your relaxed focal point so close that the front sight is excellent, but the target is too blurry.

FWIW, I totally agree with this principal. You don't want or need a prescription that gets the front sight sharp when your eye is focused at infinity (to use the camera metaphor; focused at extreme distance).

This is what reading glasses usually do. It is also what many optometrists will do because they don't understand the needs of shooters.

Although you must be able to focus your eye on the sights, you only need to be able to do this with your eye focused for close-in work, not focused at infinity. With your eye focused close-in, you will still be able to physically adjust the focus of your eye further out and be able to see the target as more than just a blur when needed, although not sharply. As an additional benefit, you will also be able to walk forward to score your target with the glasses on and not trip over your feet because you can't see more than four feet!

[David W. Johnson]

I don't need anything for seeing at a distance. Are you saying I need .75 for pistol shooting?

FWIW, I've shot for many years. Focusing on the bull was never part of my question. I just noticed it has gotten more blurry when I use glasses that enable me to focus on the front sight.

[Rover]

.75 MAY be too much. I am farsighted and only use .50.

[paw080]

I don't need anything for seeing at a distance. Are you saying I need .75 for pistol shooting?

FWIW, I've shot for many years. Focusing on the bull was never part of my question. I just noticed it has gotten more blurry when I use glasses that enable me to focus on the front sight.

David, isn't it time to go have your eyesight examined and corrected by a

professional(Optometrist/Ophthalmologist) ? Quit talking about what correction

and actually count the horses' teeth. The eye refraction(exam) will also reveal

any cylinder correction that is necessary, in addition to diopter correction

for your dominant eye, to your front blade distance, from your shooting

stance. Conjecture is BS.

Tony

[Shooterer]

For what it is worth:

In the past, Art's wisdom and Bob Jones glasses have made my life much clearer.

[David W. Johnson]

The Army requires that my eyes get examined every year. Every year, they tell me the same thing. I'm 20/20, but presbyopic. They tell me I can get reading glasses at the store, or they can order me reading glasses. If I read Dr. Wong's stuff correctly, that is what he would recommend as well.

[Rover]

I guess you all could have looked here:



http://www.pilkguns.com/c16.shtml

[David W. Johnson]

Ha! Thanks, Rover. My search never turned up the one that was right next door (so to speak). I think that article explained it well enough to summarize that experimentation is necessary. I guess I was looking for a way to reduce the options some.

Appreciate everyone's input.

David

[ShootingSight]

The math I proposed is exact and infallible, in that it represents the offset between a perfect infinity focus, and a focal point where your depth of field is centered between the sight and the target, giving you relatively the same focus on both. You don't get to violate laws of nature.

What is slightly less precise is where your eyes focus when they are totally relaxed. Most people who are 20/20, but are just presbiopic will focus close enough to infinity that the +0.75 for pistols and +0.50 for longer rifles is what you need. However there are also some people who focus near, but not at infinity, so they might find their ideal lens is 1/4 diopter off.

Bottom line, you want an optometrist to give you a distance measurement. Ideally, you want it done while dilated, and you want it done to a 1/8 diopter sensitivity. Then you can add the optical math I outlined.

The other option is to ask the eye doc to put an eyechart at 2x the distance to the rear sight, and obtain your best focus at that point. For most people, that is close to 48 inches away, because you hold your pistol so the rear sight is about 24 inches from you. Obviously, arm lengths vary slightly, but since lenses need to be rounded to the nearest 1/4 diopter, minor variations get washed out.