Eye issue? Target too blurry to center in front sight...

[trax]

I'm 33, and apparently my vision isn't what it used to be in college...

When I'm in position and looking through my sights, I have no problem focusing on my front sight and seeing it clearly. However, when I do, the target isn't just fuzzy like you'd expect--it's also non-circular, which makes it really hard to center it in the floating aperture. Even in prone I'm finding it very difficult to keep my shots inside the 8 ring, simply because it's hard to tell when I'm properly centered on the target. (EDIT -- by "non-circular", the best way I'd describe it is an irregular blob-like shape, like a scrambled egg in a frying pan).

Setup-wise, I have an Anschutz 1907 with 7020-series sights. On the front sight I'm using a 3.0 clear floating aperture. On the rear I have an 9781 rear iris / polarization filter / color wheel which I currently have set to "straight through" (full brightness, no filtering). For eye protection, I'm using a pair of $10 Peltor shooting glasses.

I'm going to schedule an appointment with an optometrist / ophthalmologist. In the mean time, are there any tweaks that I can make to help alleviate this issue?

[Erud]

Do you wear glasses normally, or have you had an eye exam recently? Round things not looking round sounds like you may have an astigmatism.

[Martin H]

Sounds like there is two issues.
1 - Your eye sight has changed. Seeing an oval target is usually a good sign of astigmatism. An eye check will show up any (eye) issues you have.
2 - Your front sight size seems to be very small. Try increasing it to 3.6 - 4.0 mm. Too small (3.0mm is too way small) will give some very unusual results. You would have got away with a small front element when you were young, but not so now as you "age". Welcome to the "normal" side of shooting :-)
Cheers
Martin

[Rover]

What they said.

Break down and get some new (prescription) shooting glasses.

[Martin Catley]

Every thing you have been told is excellent advice, if I may make one comment though. Have you had a good look at the safety glasses you are using? You say they are $10.00 safeties, if they are plastic lenses you may be getting a distortion from them. Eye safety is paramount but you do not see a lot of them being used at a top level. Have you tried looking at a Target without them?

[trax]

Thanks for the great feedback guys. I'll tweak my front aperture size, and also get an appointment with an eye doctor ASAP. I've never worn glasses before, but I guess there's a first time for everything...

[bugman1955]

You can also try raising the cheek piece a bit.

[jerber]

Get an eye exam!
I had the same problem last year
Maybe not as bad as you described but I had a hard time focusing on my front sight and/or the target
Now I wear bifocals
If was hard to get used to but I can see much better
The bad thing about bifocals is that the bottom part of the lenses is for close up and midway up is for farther object
So when I aim,I need to tilt my head for the sweet spot so that my front sight is focused

[Tim S]

Yep, see a good optician, and get a prescription lens just for shooting. Typically with aperture sighted rifles your distance prescription (including any correction for astigmatism) + 0.50 dioptres seems to work. The extra +.50 will focus your eye ahead of the foresight at a point where the foresight is still sharp, but the target is much less blurry. If you have a long extension tube on the barrel, the addition to your distance prescription may need to be tweaked.

As a warning, not all opticians understand the needs of rifle shooters and some assume that good distance vision to see the target clearly is enough. I know of one who was shown aperture sights, and thought the effect of the rear aperture would be enough. It was not.

I'd also agree with the front aperture being mush to small, unless your barrel has been shortened considerably. As Martin H alluded to, a very small aperture isn't great. With a 1907 and ISSF targets, the aiming mark will appear to be about 2mm across, so in your 3mm aperture, there is only a very narrow gap around the target. This matters because there is not a sharp step from the dark ring to white background. The inner edge of the aperture is actually fuzzy due to light coming in at an angle refacting, so it's not where you think it is. A larger aperture puts this further away so there is more "clean" light around the target. In short with a very small aperture it's possible to overlap the ring and target (so you aim well off-centre) without noticing. A too-small aperture can also hinder shot release as it's harder to tell when the sight picture is correct so you hang on the trigger.

US NRA targets are I believe slightly smaller than ISSF, so a smaller aperture is appropriate.

[Rover]

Bifocals may let you see better, but they are NOT the answer to a shooter's prayer. Go for the specialty glasses.

[redschietti]

I have recently discovered that i have a scar on my cornea.. My exact eye position determines if its clear or blury. Add that to the list old man!

[jhmartin]

Jim ... I'm on my 2nd cornea in my Rt eye. Still on the 1st in my left.
Had them done originally when I was about 20 ... supposed to last about 15-20 years.
Got double the expected out of the right and the left is fine except for some lens clouding.
Make a huge difference.

[redschietti]

Thanks! Ill keep that in mind.

[trax]

A quick update from today's session at the range. Removing my safety glasses definitely helped a bit, and I was very surprised that moving to a larger front aperture helped as well. I threw a 4.0 in there and the target is substantially more circular now. I could probably use to drop down one step to a 3.8, but this is definitely progress while I find an eye doctor.

[trax]

Another update. I made an interesting discovery at the range last night, which had a massive improvement on the quality of my sight picture!

So, as I mentioned in my original post, I have an AHG Anschutz model 9781 rear iris and polarization filter. Since my rifle and equipment was in storage for the past several years, I had the rear iris assembly and rear sight separated into their original boxes. When I put everything back together a few weeks ago, I made a simple but important mistake about how I installed the 9781 iris/filter assembly onto my rear sights.

Notice in the exploded diagram below, that the 9781 features two similarly-shaped nuts on the left side. Part "A" is a lock nut, and part "B" is called the thread flange.



The picture below shows how things look when they're assembled:



The mistake that I made was that I had backed off the lock nut and thread flange, and mistakenly thought that they were meant to help secure the iris assembly onto the rear sight, so it wouldn't come loose when spinning the various adjustment dials. In other words, I was using them to press against the rear sight, instead of using them to keep the pieces of the iris together like they were designed to do.

Sure enough, once I took the assembly off and secured parts A and B against the rest of the iris, the quality of the sight picture improved tremendously--and it became a lot easier to keep my shots inside the 9 ring.

I feel pretty foolish for not realizing this sooner... but hopefully someone else can benefit from my mistake!

[Martin H]

Hi
Just a small point about the two locking nuts on your iris. The rear one clamps or holds the iris unit together as you have described. But the front nut locks against the rear of the sight and allows you to lock the iris at the correct orientation so you can see the reference marks on the iris. Just wind the iris in, position it correctly with the reference mark at 12 o'clock. Then then lock the lock nut against the rear sight using the little C spanner that is supplied with the iris.
Martin

[jenrick]

For the bi-focal shooters, it'll look funny but it works, just flip your glasses up side down. One of my co-workers does it when we're teaching distance shooting, and it works like a charm. No need to change head position or anything else this way.

-Jenrick

[GaryN]

I think my experience in AP applies somewhat to rifles as well.
I worked with my eye doc to determine the prescription for my shooting lens. We had to balance being able to see the front sight clearly, and still be able to see the target well enough to aim. Make the front sight REAL SHARP and the target turns into a fuzzy gray cloud that I could not see well enough to aim at.

What I am saying is that you need to call around to find an eye doc that understands YOUR shooting needs, and is willing to work with you on that.
My eye doc even let me bring my AP into her office do do the tests. We did it a lunch so we could use the hall to set up a target at 10 meters, and work on determining the prescription, which happened to be exactly what Warren Potter recommended.