Rifle Scopes Astigmatism Test: Check Your Eyes in this Thread (Tips, Charts, etc...)

[BobD]

* Read trick below, above the pictures for using your iron sights to confirm the results of this test


Astigmatisms not only effect your ability to see reflex and holographic sights, but traditional riflescopes as well. For those who are not familiar with them, an astigmatism (simply put) is an irregularity in the shape of your cornea that causes refractive errors. Essentially, because it is not properly circular in shape it causes a wide range of visual distortions that can range from barely detectable to debilitating.


Well, so what you may be asking. Many of us can drive, work, shoot just fine (or exceedingly well) and made short work of the eye chart at their local DMV. It's important because if you do have this issue, your vision can be improved upon and corrected. This means no matter how small or to what degree you may have it everything WILL look MUCH better. After correction, the difference can be as noticeable as the bold type used for this sentence. Not only will your Eotech/Aimpoint look as it does in photos (very thin and sharp) but the reticle in your scope will stand out bold and easier to read. This is similar to how much darker and bolder my reticle appeared afterwards. All of your scopes will look nicer and you will notice resolution that was previously undetectable. Because contrast can be limited, your ability to see bullet holes will likely improve as well.


Not too long ago I discovered the degree of astigmatism I have in both of my eyes. Now corrected, it is an incredible difference.


-Astigmatisms are very common (affecting nearly 1 of 3 adults) and you don't have to have near/farsightedness accompanied with it. Many go unchecked as did mine for years, not knowing how much I was missing from my vision.


-Additionally, if you already wear glasses (for near/farsightedness and have not been reevaluated its possible that although your visual acuity is the same, an astigmatism could have developed in one or both eyes (even though your lenses are still very helpful).


*These tests below are by no means official or definitive. I'm not an optometrist or ophthalmologist, who would use a keratoscope to discover and evalute the nature by measuring your cornea but these views below will give you a pretty good idea as they are fairly standard for evaluation.




To properly view these images, you Will have to adjust the distance you are sitting from your screen depending on your display (computer, tablet, phone etc...).

Although an astigmatism can effect viewing at all distances, you should back up several feet, as far as possible while still clearly making out the lines in each of the diagrams.

This could range from 2-10 feet depending on the size of your display and how large the picture is formatted. You should back up until you can no longer distinguish the image then approach to focus.

Try viewing it at different distances but with only one eye at a time. Cover your other eye, don't close it as you will naturally strain to view.

HOW TO TAKE THE TESTS

​

• In each image you will see a group or set of lines in different directions with spaces in between them. The lines in the images should be a sharp bold black color that is spread absolutely even throughout the image (except bold white lines in first image).
• Images that have multiple boxes or lines facing different directions should appear EXACTLY the same (shape, size, length, contrast etc...)
• The images although different are perfectly symmetrical, there should be no illusions where any part of the shapes look narrower, darker, lighter etc.
• Take notice if when looking if your eye is drawn to just a section of the image, such as the narrow top and bottom.
• Again, no portion should look more clear than any other part. All of the lines should remain the same clarity at all viewing distances. When an image fades from being too far back, it should do so evenly, alongside any other piece of the image.

UNDERSTANDING THE RESULTS​

• There are 2 examples in the following pictures and posts that demonstrate the same image but with exaggerated astigmatic results (yours may not be anywhere near this bad or could be of a different type or from a different curvature.
• The appearance of gray in any black or white spaces is an indication of an astigmatism.
• The loss or reduction of edge sharpness between lines is also an indication.
• Astigmatisms form in many different levels of severity and angles. (Complete grayness or loss of contrast is not the only prerequisite) Because they are irregular shapes they tend to display as so (from the circle/semi with straight lines, many may appear normal where only a few may not be as easy to distinguish)
• Because of the irregularity, the circular image (with circular lines) could show a loss in contrast or graying in the shape of a bow tie, it may be subtle.
• Lines that appear bolder (or not in focus) facing one direction opposed to another is another indication of the presence of astigmatism.
• If you notice any of the above or different irregularities in the images, try either turning your head or the image to the side. What you're seeing should be reversed and is an indication of the angle of your astigmatism.

*Note: the second picture is an exaggerated example of ones appearance. Notice the graying next to the blocks labeled M.


******* Trick********

I've discovered something interesting I'd like to share as some of you get a chance to look through these. At home, most of us have a correction for astigmatism laying around or mounted atop some of our rifles.

• When going through these, look at the picture with one eye blocked as described, then look at the same image through the small aperture on one of your iron sights.
• Must be the small aperture- because of its circular shape it blocks light from entering any outer irregularities and only the rounded center portion of your eye.
• If you have an astigmatism, the difference should be immediate. This is similar to a step performed by an ophthalmologist where they ave you look through a small disk. If no irons available, you should be able to use a tac to make a similar size hole in a piece of paper

Sorry about the strange pic sizes, try enlarging the first two, I think they are quite helpful.

Feel free to add, comment or ask anything if you think something may be more useful and lease share what your experiences were.
Hope this helps-

 

[BobD]

Here's another couple images. Again, remember to step away from your display.
Everyone's distance may vary and part of that will also be dependent on your regular visual acuity. If you are using a tablet, arms length is too close. You shouldn't be able to read the writing from this post.


Step back to where you can no longer see the images clear at all and then come forward until you can just define it.


** I will mention again if not seen in the above post... Try swapping out the small aperture of an iron sight (must be the SMALL) and viewing. If this clears up any distortion, you're likely on to something.
You can try using a tac or other small object to puncture hole in a piece of paper to look through, it should have a similar effect (must be round and small opening, just enough to see through.


This next picture of a starburst has an extremely exaggerated example of one type of astigmatism next to it. Start off by looking at the center closely and backing up. Pay attention to loss in contrast, clouding toward the outside or center as well as any asymmetrical distortions. Also pay attention to the fine lines around the center dot, nothing should look shiny, dull, larger or smaller than up close. Get back from the image as far as possible, some displays can be 8-10 feet.

In this next image, review all four of the squares up close. Then focus (one eye covered at a time) on the upper left image while backing up. Keep going until it starts to lose definition, check if any of surrounding images up close are the manner in which you are losing it. When definition is lost, place the small aperture of iron sight over your eye and see if you can now distinguish the square better, you should be able to see the different types of other degrading images clearly and read them, not just that they look different.

Again, feel free to post any results, questions, etc...
If you already wear glasses, check if they are still fully correcting the image

 

[BobD]

Editing trouble, having difficulty modifying original post

Here's an enlarged version of the first two pictures from the first thread. Sorry, I feel this one is helpful and am having trouble editing the original post. This one is usually very easy o detect when there are problems. When I look at it, the vertical white lines are brighter and more distinct than the horizontal pair.


The second picture in this has exaggerated examples of astigmatisms. In the first picture, both squares have white lines of equal size, brightness and spacing. You should not see the lines facing a certain direction looking less bright or fading. The circles should not bleed in any direction either.

Below are some of the examples

 

[tiNdvenTFHwMdqKW]

I have it in my right eye.

What did you have to do to get it corrected?

 

[BobD]

There are a few options,

1) Glasses with cylindrical correction
2) Gas permeable Toric lenses
3) Surgery

I made an appointment with a local ophthalmologist who did the standard tests and wrote the prescription. Took that to optometrist where I purchased glasses with HD lenses, anti glare coatings etc... Ive only had them a short while but I'm very happy with them. I have plans to be fitted for the Toric lenses that were recommended to me in another thread I started about this. I hear Bausch and Lomb are the way to go. If I remember correctly, only the harder lenses are able to correct for astigmatism.

How are you eyes in general? Are you right eye dominant?

 

[tiNdvenTFHwMdqKW]

There are a few options,

1) Glasses with cylindrical correction
2) Gas permeable Toric lenses
3) Surgery

I made an appointment with a local ophthalmologist who did the standard tests and wrote the prescription. Took that to optometrist where I purchased glasses with HD lenses, anti glare coatings etc... Ive only had them a short while but I'm very happy with them. I have plans to be fitted for the Toric lenses that were recommended to me in another thread I started about this. I hear Bausch and Lomb are the way to go. If I remember correctly, only the harder lenses are able to correct for astigmatism.

How are you eyes in general? Are you right eye dominant?

My eyes are fine but red dot's are blurry. I think I'm right eye dominant.

I might get added to my wife's vision plan and then go see an ophthalmologist.

I hate wearing glasses of any kind. I'd rather just get surgery if the costs and risks were reasonable. Of course, it all seems a little excessive just to not have blurry red dot sights.

 

[slivoman]

Definitely tag for later reading. Thank you so much for this!!

 

[stephen_allen]

I already know I have an astigmatism, but only because the optometrist told me. I've never experienced the affects of it until now. Through my left eye everything looks normal. Through the right eye, there is gray where it should be white and all the lines are different lengths and I see halos/ghost images of what I'm looking at. If I hold my tablet and move it around, the lines on the yellow image appear to move and shorten/lengthen themselves. Crazy stuff. Makes me realize I need to wear my glasses when I shoot.

I'm right handed, left eye dominant with astigmatism in my right eye. I shoot right handed.

 

[BobD]

More added: will consolidate original post and replace some images

I've created a few examples to add to this list that I'd like to share. 3 of the following photos were modified to emulate what one sees with a 90 degree astigmatism. It is the direction that I personally have and is very common.


A couple are slightly exaggerated to demonstrate more clearly. Note: these can also better be used to detect for astigmatism as well. I will explain with each photo.


In this first example we have the open directional wheel. What is displayed here is a blurring and loss of contrast outside of the 90 degree axis. As you can see, the vertical lines show up bolder and more distinct. There are several around absolutely vertical that come in pretty bold as well. The affected area can be different for everyone and does not invalidate any possibilities if you experience a lesser or different degree of distortion.
* Try turning your screen so that the dark lines on the top and bottom are now horizontal. Pay attention to whether or not the original bold lines lost saturation, thickness, look similar to the other markings. etc... Also note any changes to the lines that are manually blurred out. The image should look the same when turning he screen or your head position.

In this next example, we have the closed directional wheel that has accompanying circular lines. Same as the previous photo, it has been altered to blur and distort at 90 degrees and has been given a 10% contrast enhancement. Note, as before lines facing vertically appear bolder and more distinct (even the potion of circular lines crossing that axis. The loss of contrast horizontally and graying (in the white areas) is very exaggerated and beyond what happens to me personally. Again, try the same test. Move the screen a quarter turn. Note any changes.

This was the Circular design from before and again has the same changes made. This is not always as apparent. This is the bow tie effect I was discussing earlier. Two large triangular masses on the top and bottom are very slightly blurred. This causes the left and right sides to appear brighter as those portions contain vertical lines. If you experienced the vertical lines graying, blurring etc... in the preceding tests than these results will likely be directly opposite what you're experiencing

Lastly we have the circular from before but the effects have been removed and should again appear as normal to non effected eyes. The circle has been stretched to more of an oval shape to create straighter lines.


Additionally, I've added a very fine gray scale on the left and right sides of the image. You should be able to clearly make out the lines between the shades of gray leading to the edge. Again, try turning your display, note what happens with the oval and the gray scale. Because my astigmatism is at 90*, when I turn my display the gray scale turns into a smudge, I can no longer make out each shade clearly. I also experience the bow tie as created in the image above

 

[gaberelli]

Thanks for posting this. I actually have keratoconus in one eye, which is a VERY severe type of astigmatism. Some of these really bring it out compared to my good eye. When I look through different optics, my good eye is very dominant and the distortions are minimal. Thank God I have it in my non-dominant eye.

 

[OldArmyGuy155]

Interesting.

 

[308pirate]

Don't you people see an optometrist at least once every two years?

This thread is dumb

 

[BytorJr]

Don't you people see an optometrist at least once every two years?

This thread is dumb

I just went. No tests like these. Just the better one or two. For 5 years I said the optometrist in FL (where I used to live) was wrong and I needed no correction in dominant eye. Headaches whenever i wore them. Just kept wearing old glasses.

Two years ago at new clinic they said script was too close to warrant changes. Fast forward to this year. New doctor (Mayo Grad ophthalmologist). You don’t need astigmatism correction. That’s why you have headaches. Oh and your non dominant eye is actually improved. Yes you need glasses for distance but at most 0.25 readers.

Effectively as I was told 10 years ago with the last good script I had. I’m perfectly blind. One eye near one eye far.

So should I have had these tests?