TargetTalk

Hi all,

I have a pair of single vision "street" glasses with the right eye lens tweaked to bring the front post into clear focus. Does it or should it matter where I "look through" the lens in regard to where the pellet lands. That is, do I need to keep my head in such a position that I'm only looking dead center in the middle of the lens? Obviously one's head is turned quite a bit to the right, you can relax your neck muscles a bit by looking through the right side of a lens rather than lining your chin up with your shoulder to access the "center" of the lens. As long as the front sight is clear and centered in the rear sight, does using one portion of the lens versus another portion have an effect on POI? Thanks in advance for answers, todd.

Champion makes a device that fits on the front of their glasses that allows you to "set-up" the glasses to your personal stance (they're adjustable in every direction) so that you're looking through the center of the lens. They work well, but you don't see them much.

I like the idea and think it's a good one.

I find with my own eyeglasses, which I use with a RedDot, it would be helpful because I can see the dot go out of round (astigmatism) when I move my head around. For my International shooting I use the Champions.

That depends a lot on the type of lens, your graduation, and how it's set up in the glasses.

For lower graduations, you can probably use all of the area of the lens with equal performance, so no lost of accuracy. The lens has the same angle all the way.
But when you go up in the graduation, the "useful" area of the lens start to shorten, until you end up with just a tiny bit in the middle that you can see trough. Those lenses don't have the same angle all the way.

When someone fits a lens to your glasses, they usually cut the lens so that the optical center of the lens is where you would look trough without any effort, so it is most likely that the optical center of the lens isn't in the center of the lens in your glasses but here your eyes look trough. That's why shooting glasses have position adjustments, so you can fine tune that.

Only someone with a set of optician instruments can say if they are adequate for shooting or not, but as a rule of thumb, if you can see the front sight with definition and without effort, it's probably ok...

But see (no pun intended) someone qualified first. Your eyes are to important to just rely on some opinions in a forum no matter how good they are.

I' m curious - how did you "tweak" your street glasses?

If you are looking through any part of the lens but the optical center, there will be some distortion of the image which will get worse the farther the line of sight is from the center. If you are uncomfortable turning your head far enough to center your pupil in the lens, perhaps you could try rotating your body slightly so that you are more facing the target. I found that if I turned my body a full 90 degrees from the target so that my eye, shoulder, hand and sights were all in line, my stance was less stable. I remember reading somewhere (tho' I'm dipped if I can remember where) that twisting the neck that much put pressure on the vagus nerve and that might cause balance problems.

Of course, if you get a pair of shooting glasses you can rotate the lens to any position you find comfortable. That is where the lens alignment device really comes in handy:

http://www.champchoice.com/detail.aspx?ID=123

Roger

I' m curious - how did you "tweak" your street glasses?

Sorry I was unclear; the prescription was "tweaked" to bring focus out to the front post.

toddinjax wrote:Hi all,
As long as the front sight is clear and centered in the rear sight, does using one portion of the lens versus another portion have an effect on POI? Thanks in advance for answers, todd.

To that part of the question the answer is no. But it's not quite that simple. As others have mentioned you ideally want to be looking through the centre of the lens and with the lens perpendicular to the line of sight, in all planes. If by tweaking you mean twisted such that it acheives the above then it should be reasonably good.

Rob.