Vision Correction for Shooters

First topic message reminder :

I thought I should start a new topic title because we're no longer discussing cataracts/surgery.

Thanks for the postings from jmdavis and mikemyers as the contents are helpful for our shooters.

jmdavis wrote:One reason the knoblochs may work better is that they may be parallel rather than at an angle to the eye

Both Knoblochs and Champion shooting glasses offer many adjustments, but they offer little protection and we may need to be concerned with the longer vertex distances (distance from the eye to the lens).  With thick spectacle lenses and larger sizes of the more conventional shooting glasses, looking slightly sideways may cause the prescription to change and also would induce prism, possibly causing BE Mike's errant shot groupings.  Still interested in his sand bag testing results.

Right now I need +1 for normal distance with my shooting eye. I have tried, +1.5, +1.75, +2, and +2.25 for irons with the 22 and Service Pistol. With good light (i.e. Perry) and no cover, I like the +2.0. In dimmer light, I like the +2.25. With the airgun indoors in good range light, I wind up using the +1.75 or the +2.0.

Well stated, and to clarify, the +1.00 distance Rx need to be subtracted from the total resultant Rx to understand the various lens power adds.  We would then read, "I have tried +0.50, +0.75, +1.00, +1.25 (adds)...."  The reason for the different powers, besides the sight radius, would be the pupil sizes as related to the lighting.

I have the paddle and also a +.125 lens for tweaking. It should be noted that getting a +.125 scrip generally means that there will be no anti-reflective coating on the lens. Maybe Xmastershooter can address that, but that is my understanding.

I'm not sure what is happening here but anti-reflection (AR) coating can be added onto any lens.  All my top level and serious shooters get the AR coating.  Keep in mind that there are different quality levels and is reflected upon the price.  I use only the top-of-the-line coating.  The cheaper ones smudge easier, flake off easier with handling, and do not work as well.

In concluding, I would recommend that people not just start buying lenses. Even though you can get them for $16-$40 each, some research will help you to not wind up with a collection of 15 or 20 lenses.  Talk to your optometrist. Read XMastershooter's writings on the subject from Ed Hall's page. Check out a variety of online resources, then make decisions.

As I mentioned before, I'll be adding onto my original "Bullseye Shooters' Guide for the Eyecare Professional" and have contacted the managing editor of Shooting Sports USA.  I've been told that this has been a very popular article for the readers.  I'll also provide this to Ed Hall as his site will show everything in its entirety, as the Online magazine may edit out some important details.  Thanks Ed!

mikemyers wrote:
Not sure if anyone else would like this, but I did all the above only for my shooting eye.  For my other eye I set them to the distance to my bench top, for working on the guns, reading, adjusting the sights, etc.  All of them should be polycarbonate.  IMHO.

I spend almost as much time determining the non-shooting eye Rx as I do with the shooting eye Rx.  There are many possibilities.

I'm wearing polycarbonate lenses and shooting standard 1" ultradots.  I generally run the brightness as low as possible and still see the dot based on the ambient lighting conditions.  I know I have an astigmatism but was wondering if this can be corrected with a prescription.

You might find this useful:

http://www.allaboutvision.com/conditions/astigmatism.htm

1.  Have fellow shooters look through your red dot scope to verify that they see the dot round and not the way you see it.

2.  Bring in your red dot scope to your eye exam.

3.  Have the doctor put your new prescription into the trial frame

4.  You must then look outdoors at a good distance and then judge the appearance of the dot.

5.  If you would like more information, look at an earlier post above that has a link to starreloader.  I'm in the process on working up a draft of some updates.

If you're wondering if the unclear dot is the scope or your eyes, here are a few other suggestions to see if you can tell which is in need of work:

1. use a camera to view the dot
2. use an iris to view the dot**
3. rotate the scope and see if the aberrations rotate with the scope

**You can make a simple pinhole lens in an otherwise opaque object and look through it, instead of buying an iris.  The edges of the hole you make should be as clean as possible.  I'd suggest 1/8 inch or smaller hole.  Cardboard is not good because the edges will be fibrous, but plastic can work well.  A friend of mine drilled a hole in a pair of dark sunglasses and used them for a while.

Pat,
  I have the same view of a dot that you are experiencing; sort of a figure 8 on its side.  From my discussions with others, I believe I have an astigmatism also but have never gone through the trouble of getting diagnosed and attempting to correct it with a prescription.  I have been on an iron sight only kick for the last 8 years or so, so the dot issue hasn't been a priority but I was able to minimize the distortion by using an iris.  I use the Merit model that is adjustable so I can tailor it to the lighting conditions.  Keeping the brightness as low as possible helps as does using the smallest size dot but my best results were using the iris.  

Good luck.
John

Thanks guys! I have a merit but haven't used it in forever.  I have a 900 .22 match tomorrow so I'll break it out tonight & see how it looks.

Always great folks & info here!

Pat

Last August I finally, after 4 years, got a routine eye exam.  I've used mt 2.0 readers early on but they but made the 2 MOA dot starry, so I shot without them for a couple years then the target started to be double-imaged last summer.  So the doc gave me a prescription and the new glasses gave me 20/20 and a clear image of dot and target....like a rebirth!   My groups didn't improve but at least I've got a much clearer comfortable image.   Interestingly, a friend visits each fall and spring and brings his scoped Ruger Mk3 and GP 100.  We shoot his Rugers and my two 9's.  In all instances at 10, 25 and 50 yds I shoot 3" above his groups; both of us holding on the center.   I would think that with a dot or scope we'd shoot the same elevation.  Could this be a prismatic difference in our eyes?

Bigtrout wrote:In all instances at 10, 25 and 50 yds I shoot 3" above his groups; both of us holding on the center.   I would think that with a dot or scope we'd shoot the same elevation.  Could this be a prismatic difference in our eyes?

I believe if you both sandbag test the zero with the red dot exactly centered within the scope, the hits would be in the same spot.  After recent discussions on scope parallax, I doubled checked all my Ultradot scopes and did notice parallax. During a Moody/Zins clinic, Brian Zins instructed us to zero in our scopes with live fire and not off sandbags because we may all have different holds.  Possibly the red dot is not centered within the scope when your shots go off.  Ed Hall has written often about the dot and looking through the tube.

I just tested "prism" by moving my eyeglass shooting lens horizontally and vertically and both the dot and target move the same amount while the dot was still centered.

John Dervis wrote: From my discussions with others, I believe I have an astigmatism also but have never gone through the trouble of getting diagnosed and attempting to correct it with a prescription.

Checking the eyes not only provides refractive measurements but also valuable information on the health, even hypertension and diabetes.  I once examined a patient who skipped an eye exam one year before he came to see me.  By then I found visual field loss from Glaucoma, a disease which does not initially affect vision and there are usually very little symptoms if any.

The aperture may always help reduce the visual disturbances but shooting sustained fire is a bit of a challenge.  If you look down the line at Camp Perry, I don't believe you'll find any shooters using apertures especially for the red dot.  I've seen the Merit suction cup fall off from the lens and the Gehmann Iris may not fit certain frames and lenses.

I'm almost finished with my updates to the original Bullseye Shooters' Guide for the Eyecare Professional and quoting from a senior world champion. "It's amazing that shooters may spend thousands of dollars for their equipment but totally ignore their vision."