thick glasses and scope zero


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heviarti
June 7, 2009, 10:57 AM
I've noticed with supposedly zeroed scopes I'm always *way* far off until I zero them, then the previous user is off. I wear extremely high refractive index lenses. A friend of mine suggested that may be causing the problem, and also may be causing my trouble hitting reliably with a shotgun. I do really well with a pistol however, so go figure. I can't seem to find an eye doctor that can tell me anything, or will tell me anything. Of course none have been able to explain the blurs that cross my vision that are not floaters, either. Anyone else way nearsighted with lots of prism noticed this? I find the glasses also play hell with the magnification on binoculars...

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PT1911
June 7, 2009, 11:04 AM
it is very possible that you just shoot differently. a little pressure here and a little pull there and someone else's zero is not your zero. and vice versa.

I guess there is a possibility of a refractive deviation but that should only apply if the glasses take up a portion of your field of view.. much like if one were to look through water from the surface vs actually immersing themselves, once fully under, the refraction issue is a non-issue.

Hungry Seagull
June 7, 2009, 01:56 PM
I read your post.

My eye surgeon had a talk with me and the wife recently. He broke out a box of prisms a small thin box with lens that bend light. Told both of us if he had to incorperate these into my glasses things are going to get complicated and expensive.

Is this what you are facing? Bending light through the lens in addition to increasing focus and clarity?

If you are seeing short lines of very bright lights that last a few moments at a time inside your eyes that cross your vision, that means your retina is pulling away from your eyeball itself a little bit.

If you are seeing what appears to be a fishbowl underwater shivering at the edges of your vision inside your vision then perhaps you have problems with eyeball's collecting light and making picture at the back in the right place for your brain to resolve into a picture of your world.


Somewhere in all of this is a spot on YOUR glasses that is ZERO for YOU, no one else.

What I do is I put a shotgun with slug on the table at the range. I line up the sight with it's dot on the large paper target that is nothing but one inch squares.

When dot is at center + I fire. Where the slug goes makes a hole. Hopefully that hole is at the + in the center of the paper where the laser dot or IRON BEAD is at.

That means zero for you (Me.. the shooter). No one else.

Sometimes slug makes hole elsewhere on my target paper. I adjust my laser sight until slug makes hole at or NEAR the + within a inch at whatever range Im shooting at.

That is MY zero, NOT YOUR ZERO.

You see...

if I threw away the fancy laser off my Remington 870 Marine Magnum and all I shot with is that Iron Bead sight at the end of the gun, somewhere on my glasses is a ZERO where that slug is going to hit the + on the paper.

If I gave my gun to you and you aim and shoot it AT YOUR ZERO through your glasses, you will hit every time.

Finding that sweet spot through glasses in zero is one of the hardest things to learn I think.

None of my eye doctors or surgeons ever talked plainly to me about how to find ZERO with my glasses. But they have not yet had to break out prisms either.

Think of it this way. WITHOUT PRISMS, the light travels in a straight line to my retina through the glasses and eyeball's lens you with me so far?

Now, IF YOUR GLASSES are containing PRISM to BEND light to YOUR retina, Your ZERO through the glasses are going to be one hell of a way off to one side or the other compared to my glasses.

Never mind what sights, beads or plain pointing is gonna result with your shooting.

I hope this longish post helps to organize your thoughts.

If you see alot of flashing lights in your vision, go to the ER or eye surgeon right away, that means your retina has detached and you have a limited time to reattach it before it is lost pernamently. Once retina is LOST, then it becomes sort of a grey/brownish/black BLANKET interfering with your vision in that eyeball.

Back to zero.


Your gun has what is called a BORESIGHT ZERO. Your Barrel will send the bullet to a point somewhere it is aiming at. It is not the same ZERO as you are looking at through your glasses or eyes.

So If you put a sight on this barrel and got it to hit bulls eye with your glasses every shot.. then you have found YOUR zero.

No one else can use your sight to hit the same target at the same range with that adjustment.

Your glasses are special to you, only your sight and your world.


Now consider this...

Your retinia collects light into a precise center at the back of the eyeball where your optic nerve picks up all the data and sends it to the brain.

What do you think is going to happen if that eye ball is unable to focus all the world onto that center of your retina back there in that eyeball?

Or worse... some nerve conditions degenerate and fail to resolve that data into a usable picture?

Thoughts and ponderings.

There are other threads about this elsewhere in the forums, some of which contain sources on the internet where one can have a lens made for shooting that clips onto your glasses for aiming with ONE EYE through that lens.

For that to work, you need the complete prescription data from your doctor with the glasses you are shooting with.

If you dont have the complete numbers or all of the numbers then such a lens is impossible.

I have not yet had to use either prisms or shoot lenses that clip onto eyeglasses. My zero is somewhere in the center of my eyeglass lens in both eyes. The right eye is what I shoot with in shotgun, I shoot with dominant left eye with handgun.

One hand or the other, sometimes both. But I always shoot right handed same as I write. I might have to contort, bend, lean, tilt or otherwise hurt myself getting my eye in the right place behind the sight so that I hit what I aim at.

Good luck!

heviarti
June 7, 2009, 11:34 PM
no, see the prism is what keeps me from being crosseyed (finally got that out of a doc about a month ago) and is measured in 'diopters' what ever the heck those are. I'm not experiencing any symptoms like seperation. I've got something up, but for years all the docs have done is ignored me and kept silent. Rather annoying, seeing as my brain is functional. I could post my 'scrip but I doubt anyone could make any sense of it.

I can take an aimed shot with a shotgun on a stationary target and not hit. Strangely it seems worst with my Winchesters... It just seems a little odd I'd be better than a foot off with a scope at 100 yards.... A friend of mine suggested this, but he's been watching me for ten years. maybe things are a li'l diff'nt out from behind all this glass.

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