Vision problems in prone

[ZD]

My vision problems in prone are extremely frustrating. I use to be able to shoot mid 190's, and an occasional higher target (199 personal best) but now i struggle to shot a 190. I have 20 20 vision, but I have stigmitism. The shooting glasses I use (a pair of Knoblochs) increase the clarity of the bull down range, helpful for 50 ft and 100 yds. However, when I shoot prone, the bull is very gray, and it seems as if I am shooting at a blur with a white center in it. All I know is that my aperature is around the bull. This would cause me to shoot a 7 or 6 low occasionally, seems as if I got an optical allusion (happened twice in 20 shots). I've experiented with aperature sizes ( I did use plastic elements, now use an adjustable glass iris from Gehmann, both of which had the same vision problems) and with my iris. I decreased the size of the rear iris. Filters seem to be almost useless indoors. I tried raising my position, it might have helped, but it was almost negligable. Interesting also is that the bull's look crystal clear until I completely line up my rear and front sight. If I misalign my front and rear sight so that the front sight sits very high in my rear sight picture, I can see crystal clear. However, I can't shoot like this, esp. since your eye's look upward. I am paranioid about my cheekpiece setting, and I even tried putting it to low to see if it helped my vision. It did not. Finally, I don't have these problems in standing usually, and only occasionall in kneeling. I shoot a Anschutz 1907 ( brand knew) in a newer generation 1813 stock (the one with the second generation Anschutz buttplate) I use an older Anschutz rear sight, with a gehmann adjustable iris with filters (no polarization). I use an adjustable clear iris from Gehmann, and I use a 3-5 in prone

[yana]

Hows yr head position?
If yr struggling to look straight forward, you might be looking through yr eye lashes.

[yana]

Might also be caused by the distance between yr eyes and the dioptersight.
This can vary per position.Maybe, if you adjust the diopter/iris etc for this distance, it helps.

[RobStubbs]

Some comments to perhaps help you diagnose the issue.

Firstly your glasses should foucus on the foresight not the bull, it should be slightly blurred.

If your head is in the wrong position you can be distorting the shape of your eyeball, or looking through your eyebrow. Both of those will alter your sight picture.

You can also inadvertently be making it worse by holding on aim too long and running out of oxygen to your eyes - they're the first thngs to go.

So some suggestions. Perhaps get someone to photograph you in position and have a look - post the pics up here is probably worthwhile. Also what foresight element are you using and what rear sight iris (size) ? Do you see a big difference between all the elements of the aiming marks - i.e. the sight picture, or are the rings close together without much white space around the outside.

Oh and do you get the same issue shooting indoors v outdoors, or is one better ?

Rob.

[BartP]

Rob's right. Oxygen could be a major issue. Lots of deep breaths between shots is a good idea. Remember, the breaths you take are actually helping you see at least 2 shots down the line and NOT the one you are shooting at that exact time - so breathing is super important from the start.

Also, if the way your face lays on your cheekpiece causes a bunching up of the cheek-skin under your eye (pushing it forward and upward), your vision can become blurred and the image of the bull can become distorted. If this is happening, you need to try building a custom form on the cheekpiece that you can lay your head on but keep that extra skin to a minimum.

BP

[jmkwyo]

I am actually right there with you ZD. I have the same problem with my eyes. When looking through the sights I can actually see the bulls that I am not aiming at more clearly than I can the on i am aiming at. It does help a lot to focus on the aperture and not the bull. It also helps to not over hold (oxygen issue they were discussing above). None the less I still feel like I shoot through a cloud in prone especially, most of the time my KN and ST are better than prone. Have you ever tried a scope?

[Bob-Riegl]

My sense in the matter that it may oxygen deficiency. However, that being said I think it is more adjustment to the shooting eye lens as far as keeping your optical center positioned correctly in relationship to the bull you are sighting. On Have someone stand over you and observe your relationships of the glass to the rear sight. If he does not see the lens is parallel to the plane of the target---you may have to turn your lens either right or left (my hunch is to the right) so that you are sighting through the centre of the lens. The position of the iris and the size to which you adjust the iris, may cause some diffraction to occur also and that will cause blurring as well. I think it's a matter of adjusting your Knoblochs' until your problem is helped. I know that I shoot AP & FP and I used to go crazy trying to get rid of blur: #1 I increase my oxygen intake 2-3X as I settle in for the shot; #2 I worked with my glasses after determining the optical center, and played long and hard with adjusting the lens so that I was sighting through (not around) the iris and the lens was parallel to the plane pf the target. Like Chicken Soup, wouldn't hurt to look into you adjustments, as the Knoblock lenses tend to get out of alignment easily and quite often. "Doc"

[NCST8]

Is your head upright while in position? Is your lens set up such that you are looking straight through it? I would be willing to bet that your head is very upright in standing and kneeling but not in prone. Therefore, your lens may not be in the right position in prone.

You don't have to see the bull well, but if it is washing out almost entirely, perhaps you should back down the power of your lens. Or, close down your rear aperture somewhat in prone.

[ZD]

I'll try to post some pictures next week. I went to practice on Thursday, with a raised position I had shot with once to see if it made a difference on how I saw. I tried putting the cheekpice on my cheekbone (to get rid of flapping skin) but I stopped shortly because it would not work comfortably and it did not help my sight picture. I shot horrendously. The sight picture with the aperature around the bull was so bad, I shot two 5's and one 6 in prone, to finish with a 172. I could have done better closing my eyes. After I was done shooting, my coach put a yellow filter on my iris, and then opened up my front aperature to a 3-7 (pretty large for prone, especially on a 26 inch barrel, no bloop tube). Vision looked great, but I only got in postion for 2 mintutes with it before cease fire was called.I then preceded to shoot a 178 standing and a 181 kneeling. No vision problems in those positions. By the way, I use a 3-8 in standing and a 3-7 in kneeling.

[jmkwyo]

3.7 isn't large for prone. I have used a 3.6 for many years. Whatever your eye is comfortable with. If you don't have a rear aperture that is adjustable you might want to try that if the yellow filter helped.

[RobStubbs]

If your coach is making suggestions and changes then how are they working for you ? Has he taken some pictures (if not then get him to) ? I still can't help thinking it's a head / eye position thing rather than iris, filter or foresight ring - but to be honest we're just guessing without seeing your position in detail.

Rob.

[ZD]

Thanks for the advice. I did check my glasses and my cheek pressure, both seemed to be fine. Seems as if opening the front iris to a 3-7 (pretty large for prone) and putting a yellow filter on has done the trick for now. Hopefully that will remain the case. Will be interesting to see what I can see once I move outdoors

[tsokasn]

Hi!
O had the same problem with you,and I thought that a grey filter in the iris and small iris diameter would help.
What really helped me out is a yellow filter(better bull-white-foresight circle contrast for my eye)breathing between shots,and not to many seconds on focusing/aiming.
Those things solved my blur in the eye(check my topic 'blur in the eye')

[Guest]

I wouldn't say 3.7 is large for prone, 4.0 is the average size and I use a 4.2

Its far easier and quicker for the eye to center a small object in large hole than vise versa

This was proven to me by my coach who could not get me to move from a 3.8 to a 4.0 early on in my shooting.

I was absolutly positive than the smallest amount of white around the target inside the fore sight ring would be more acurate.

To prove his theory above he had me sight in then he changed the target to a blank card with a penny placed in the middle of it a 50m.

I could barly see it a 50m, but he told me to fire one perfect shot at the penny, the result, I hit it with the first shot.

I then backed down and used the 4.0 which resulted in an improvement in group size and consistancy

[BartP]

The individual-specific aperture used will be dependent on the sight radius of the rifle. It looks like most of you are discussing a standard 26-27" barrel length - some with tubes and some without, I'm guessing. Either way, the aperture width is going to be relative to the length, how your eyes work, the lighting conditions, and how much space you are comfortable with around the bull.

My barrel is 19.75" long - a short one. Add the tuner and the tube and it reaches 39.5". My front aperture is 4.4-4.6 depending on light conditions.

Find a comfortable sight picture, take in a crapload of oxygen between shots, make absolutely sure you are hydrated, and don't let the skin of your cheek ride up under your eye (distorting the shape of your eye), make sure you blink (and blink often - HUGE DEAL) to make sure you have not imprinted, and you should be shooting tens - assuming you have the other fundamental elements of your position and process down pat.

Bp

[Cadet]

A personal opinion, may not meet with general agreement, but works for me. Centering in the rear aperture is of minor importance. Consider the size of the rear aperture, and that you must be using an area of it, not a single point, to get appreciable light through. So whatever you do with the rear aperture in the sight picture, you can not move the point of aim much. So if you get a clearer sight picture with the foresight with the target centered in it placed off center in the rear aperture, shoot that way. In any case, if you produce the same sight picture each time, you must get a consistent aim. I have a cataract problem, and can not shoot with the sight picture centered in the rear aperture. What I am actually doing when I move the foresight/target pair round the image of the rear aperture is moving the incoming light image, which can only be 1 mm wide at the most because of the rear aperture size, to different parts of the lens of the eye, and for a clear image, getting between bits of the cataract growth. I only get a clear sight picture when I use the extreme top right part of the rear aperture field, so I shoot that way all the time, with only slight variation for when the cataract moves around a little. I could talk about dealing with cataract, too, but that was not the question you asked.

[Kiwi bob]

Being 68 I can relate to these vision problems when sighting in the prone position.
My problem is a mirage or ghostly circle that sits at about 12o/clock and is most annoying.
If I remove the cheek piece and use a rest I get a clear sight picture. My optometrist can only sugest that it is my old face going flabby and pressing up on the eyeball which has gone soft and gets distorted.

Kiwi Bob

[ZD]

Thanks to all who gave me advice. I did check my glasses, cheek pressure, breathing ect. Seems as if a 3-7 apperature size and a yellow filter did the trick. Oh, and I probably should have specified that I am 17 years old. I apologize to the established gentlemen who may have posted advice under the allusion that I was older. Again, thanks for all who posted.

[Telecomtodd]

Hats off to this young man with wisdom beyond his years. He referred to the earlier correspondent as an "established gentleman" instead of the normally heard "old fart" moniker.

On behalf of the other "established gentleman" and my own severely reduced hairline and "established" waistline, I thank him!