Astigmatism and shooting

[blackcat_attilio]

Hello to everybody!
On last Sunday I went to the range to shoot my M91/30. When I was there I don't know exactly what was in my mind.... the heck I decided to shoot without my glasses (I'm astigmatic) !!! I used only protective glasses.
2 series per 10 shots each, target distance 100m / ±110yds, no scope. The result you can see on the attached pic. I'm satisfied even if I think (I'm sure) I can do better.
I must say when I use my "ordinary" glasses my score is not much better; only the groups are just a little bit more close.
Anybody else is astigmatic and has / had troubles at the range?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[GRF]

My wife is right handed left eye dominent with astigmatism in both eyes, when shooting clays she must find the bird with both eyes and then shoot with her right eye closed. If both eyes are open she will see either one bird and two beads or one bead and 2 birds. I have an astigmatism in my left; non dominet eye and have no issues as the right over powers it. GRF

[Kirk]

Without glasses, I have my choice of three front sights; the gray one on the left, the black one in the middle or the other gray one on the right. There are really just two front sights which overlap, forming the black one in the middle. Unfortunately, one front sight is higher than the other so the middle one has a gray fuzz on top.

[Patrick Chadwick]

Blackcat, those of us who are "of a certain age" are very frequently afflicted by astigmatism. You are very definitely not alone!

No, I am not old, just a teenager - 5th time around. But I have it worse - an optical fault (rather like the inclusions you find in good old-fashioned glass marbles) causing a double refraction. That means that I truly see double in my shooting eye. I have to concentrate on the lower picture, otherwise I get twin groups, about 3 MOA apart!

However, your targets do not show the typical asymmetry of astigmatism, probably because any astigmatic effect is drowned out by pure fuzziness. The first thing to note is that reduction of the optical aperture will improve matters. So looking through a peepsight is the first step. The fuzziness will be reduced to a considerable extent if, for instance, you look through the backsight of an Enfield No. 4, M1917 or 03-A3. Try it!

So whatever your glasses, fitting a variable aperture onto them, such as the stick-on iris made by Gehmann, will help a lot. As you reduce the aperture you will find that the sight picture sharpens up, until a point is reached where it all goes grey and spidery lines appear across the field of view. Back off a bit from that point, and you will have got the right aperture for that level of lighting. As the optimum depends on the light level, a variable aperture is a must.

If you have astigmatism, you will probably now find that the optimistically sharp lines of the backsight/foresight shown in many books on "How to shoot" are not at all sharp, but rather fuzzy. With an aperture backsight and ring foresight you can simply aim at the middle of a symmetrical fuzzy picture and all is, more less, OK.

However, just about all service rifles have a blade foresight, and most have an open backsight. This means that you can easily hold the horizontal position, because of the left-right symmetry. But the vertical position is very uncertain, because the top of the blade is fuzzy. So "6-o'clock hold" is rather somewhere on a vertical line. The result is that you may achieve good horizontal spread, but a vertical spread that means if you shoot long enough the target will fall into two halves.

If you are a car driver, then it is pretty sure that your optician will have optimized your glasses for a distance of around 25 yards. So you have a sharp picture of the grass halfway down the range, but cannot see backsight, foresight or target clearly. Reading glasses are a bit better, but they are optimized for a distance that is too short - something like 50-60 cm. You need glasses that are optimized for shooting. That means they must be set up so that the astigmatism is corrected for a distance of about 90 cm - for the foresight, not for reading number plates at 25 yards! If your optician cannot/will not do this, find a different optician.

There is another effect common to advanced teenagers, called presbyopia. This is quite simply the lack of visual accomodation, usually acompanied by a lengthening of the near distance, that comes with increasing age. There is no cure for this. All you can do is reduce the aperture as far as you still have a clear sight picture, and make sure your glasses are optimized to see the foresight.

Of course you can move over to shooting with a telescope. Then you will be worried how the target moves around as your heart thumps!

In short, you can't win. But with properly matched glasses and either a rifle with an aperture backsight or an iris fitted to your glasses, you can improve matters a lot.

Hope this helps!

Patrick

[blackcat_attilio]

Hi Patrick! Your post is very interesting! Let me have some minutes and "I will work on it". It's interesting! Thanks.

[Calfed]

I too have presbyopia, astigmatism and a touch of nearsightedness.

I usually wear progressive lenses to correct for all three. However, when I shoot, I wear only the distance correction, nothing for the presbyopia. This is because progressive lenses "blur out" when viewed off axis as you do when you shoulder a long gun with a proper cheek weld.

I notice that your age is listed as 50 in your profile--prime time for a raging case of presbyopia. If you are wearing progressives, you might want to try using a pair of glasses that correct your astigmatism only--no "reading correction".

[Patrick Chadwick]

Calfed is right. I tried progressive lenses - fell over my own feet going downstairs (when you view strongly off-axis) and for shooting they are totally impractical (sight picture varies with the smallest head movements). You must have glasses with correction optimized for the distance to the foresight. Anything else is a false economy, and as a result a waste of money on ammo that would be better spent on getting the correct lenses!

Patrick

[blackcat_attilio]

I too have presbyopia, astigmatism and a touch of nearsightedness.

I usually wear progressive lenses to correct for all three. However, when I shoot, I wear only the distance correction, nothing for the presbyopia. This is because progressive lenses "blur out" when viewed off axis as you do when you shoulder a long gun with a proper cheek weld.

I notice that your age is listed as 50 in your profile--prime time for a raging case of presbyopia. If you are wearing progressives, you might want to try using a pair of glasses that correct your astigmatism only--no "reading correction".

Calfed is right. I tried progressive lenses - fell over my own feet going downstairs (when you view strongly off-axis) and for shooting they are totally impractical (sight picture varies with the smallest head movements). You must have glasses with correction optimized for the distance to the foresight. Anything else is a false economy, and as a result a waste of money on ammo that would be better spent on getting the correct lenses!

Patrick

Hello! I thanks you, both !
My trouble is I see right near and in the distance but not "clear"; on these last days a news came: I discovered I begin to have "problems" reading newspaper... So I'll try to use progressive lenses. Said that, up to today at the range I used lenses optimized "for astigmatism only".
Now I want try to shoot 20 rounds without glasses and 20 using the "stuff" Patrick told me in the post above - before must I find them in the shops...
Anyway, keep in touch. As soon as I'll go to the range I write what about.

[TDH]

I am now pushing the big 6-0 and I've had astigmatizim since I was in the 4th grade. You know back in the days of the one class room caves. I also am nearsighted. I've had progressives and could never get used to them so I went to regular bifocals. Smaller lensed glasses make bifocals work funny as well because you are trying to pack too much into too small of bag if you get my drift. I have special glasses made up for computer use and I would suppose now that they would also have worked well when I was still welding. I actually considered having a pair made with the bifocal on the top of the lense because trying to see through tyhe bifocal on the bottom while trying to weld over is literally a pain in the neck. I also have a pair made without the bifocal for just distance. Bifocals and golf swings also have compatability issues. On a final note I was shooting my bow and noticed with one pair of glasses the target was just blurry with one pair of glasses but clear with another. I asked my eye doctor during my next exam and she checked both pair and they were both within tolerences for my prescription. one being on the high end and the other being on the low end. The high end was better for long distance than the low end. Talk to your eye doctor.

[blackcat_attilio]

I am now pushing the big 6-0 and I've had astigmatizim since I was in the 4th grade. You know back in the days of the one class room caves. I also am nearsighted. I've had progressives and could never get used to them so I went to regular bifocals. Smaller lensed glasses make bifocals work funny as well because you are trying to pack too much into too small of bag if you get my drift. I have special glasses made up for computer use and I would suppose now that they would also have worked well when I was still welding. I actually considered having a pair made with the bifocal on the top of the lense because trying to see through tyhe bifocal on the bottom while trying to weld over is literally a pain in the neck. I also have a pair made without the bifocal for just distance. Bifocals and golf swings also have compatability issues. On a final note I was shooting my bow and noticed with one pair of glasses the target was just blurry with one pair of glasses but clear with another. I asked my eye doctor during my next exam and she checked both pair and they were both within tolerences for my prescription. one being on the high end and the other being on the low end. The high end was better for long distance than the low end. Talk to your eye doctor.

Hi! Thanks for your advice! I'll try this way too.