Astigmatism and red dots
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earlthegoat2
Member
Is it a cheap optic?
I have astigmatism in both eyes and tend to see a starburst. Green helps and Holosun 507s and 510s with the circle dot seem to give me the best compromise.
I have astigmatism in both eyes and tend to see a starburst. Green helps and Holosun 507s and 510s with the circle dot seem to give me the best compromise.
Tried a tru glo and Sig Romeo 5, MRP, and the higher end Romeo 5. Tru glo was super bright around the edges. Romeo 5 was kinda blury, the MRP was same.
CapnMac
Member
Well, astigmatism varies, and, as a result, the perception of dots will vary too.
A blurry ring is likely the best possible outcome--this is better than spiky starbursts or a "sawtooth circumference" (unless you can get comfortable with those).
Some of this can come down to practice, of getting the 'habit' of paying less attention to the dot, and more on the target (which may not be easy, especially if the dot, as perceived, has expanded to be larger than the target).
YMMV
A blurry ring is likely the best possible outcome--this is better than spiky starbursts or a "sawtooth circumference" (unless you can get comfortable with those).
Some of this can come down to practice, of getting the 'habit' of paying less attention to the dot, and more on the target (which may not be easy, especially if the dot, as perceived, has expanded to be larger than the target).
YMMV
v8stang289
Member
If you look through an aperture or something with a small circular opening while looking through the optic it allows you to view the actual shape and size of the dot.
As in Eye => aperture => optic
That might give you an idea of the quality, etc. And weather the flaring is the optic or you.
I have an astigmatism and discovered this by accident when I flipped up my rear BUIS on my AR while looking through a Sig Romeo.
I'm playing around with designing and 3d printing an aperture that snaps on to my glasses to aid in shooting handguns with Reflex sights.
As in Eye => aperture => optic
That might give you an idea of the quality, etc. And weather the flaring is the optic or you.
I have an astigmatism and discovered this by accident when I flipped up my rear BUIS on my AR while looking through a Sig Romeo.
I'm playing around with designing and 3d printing an aperture that snaps on to my glasses to aid in shooting handguns with Reflex sights.
Lefty38-55
Member
Here's HOW to tell if a cheap optic or astigmatism!
Rotate the optic (around the optical axis ... not end-for-end, LOL!) while looking through it and if the 'flare' follows the rotation ... it's you.
Rotate the optic (around the optical axis ... not end-for-end, LOL!) while looking through it and if the 'flare' follows the rotation ... it's you.
dieselchief
Member
i see a figure eight at a angle....use the bottom one for a aiming point.
Howland937
Member
Definitely recommend green. Red dots look like commas...or comets. Brightness setting low as tolerable helps. I only have one red, a Holosun 507 Competition. It's got the multi reticle, so I can pick the one that works best at any given time. All my others are green or green circle/dot.
Mizar
Member
I might sound quite rude and uneducated for some, but if red dots are giving you so much trouble, why not just use the irons instead? At least they are working (if they are in a proper configuration)...
The Glockodile
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- May 6, 2020
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- 1,688
Most of the LED tech and glass for this kind of equipment has been worked out to at least the “above average” level, much like our little AR cottage industry.
Raise the rear iron sight, and use the pinhole aperture.
If the red dot flare is attenuated, then the likely cause is astigmatism.
You might remember this particular test / maneuver from your Optometrist or Ophthalmologist.
Raise the rear iron sight, and use the pinhole aperture.
If the red dot flare is attenuated, then the likely cause is astigmatism.
You might remember this particular test / maneuver from your Optometrist or Ophthalmologist.
Howland937
Member
For me, a front dot or post is even harder to decipher than an illuminated dot. I can get by not using any corrective glasses or contacts, but speed is greatly reduced if shooting at smaller targets. So, optics on competition/fun pistols.
Jonah77
Member
- Joined
- May 13, 2023
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- 147
I didn’t see it mentioned yet so here goes:
Prism Sight
I have an astigmatism (confirmed). I happened to notice that while using my Vortex Spitfire Prism I had no issues with blooming or blurring. The dot was crisp and clear (red or green-the Spitfire has both).
I sold off my two Romeo 5s and added two more Spitfires.
I have a Holosun HE530GC (currently in the drawer) and a Trijicon RMR that I use on an AR, but the prism sights are the clearest and easiest to use when accuracy and speed count.
If I were a starting from scratch I would take a look at Primary Arms for an inexpensive (but high quality) model, or borrow one from a friend to see if it works for you.
Note-1: This is not unique to me. If you do a search you will find others share the same experience.
Note-2: Prism sights use an etched reticle and work very well in daylight without even turning the dot on.
Prism Sight
I have an astigmatism (confirmed). I happened to notice that while using my Vortex Spitfire Prism I had no issues with blooming or blurring. The dot was crisp and clear (red or green-the Spitfire has both).
I sold off my two Romeo 5s and added two more Spitfires.
I have a Holosun HE530GC (currently in the drawer) and a Trijicon RMR that I use on an AR, but the prism sights are the clearest and easiest to use when accuracy and speed count.
If I were a starting from scratch I would take a look at Primary Arms for an inexpensive (but high quality) model, or borrow one from a friend to see if it works for you.
Note-1: This is not unique to me. If you do a search you will find others share the same experience.
Note-2: Prism sights use an etched reticle and work very well in daylight without even turning the dot on.
Last edited:
It’s not rude. The one place I think a dot stands out is in the dark with a weapon mounted light illuminating a target. You’d want the brightness cranked up a little to not get washed out by the light. Otherwise, I’m pretty comfortable with iron sights.
westernrover
Member
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- May 4, 2018
- Messages
- 1,613
I have astigmatism in one eye and not in the other. It's quantifiable also. On my prescription, the cylinder is "0.50" (and there is an axis that specifies the orientation of the astigmatism in 180 degrees).
Looking at a Trijicon slide-ride type mini-reflex, the 2.5 MOA dot is a starburst with either of my eyes. With the astigmatic eye, the burst is elongated vertically (the orientation of the astigmatism) so that it looks like a tiny octopus with legs hanging down. With lenses that correct the astigmatism, it looks like a round starburst.
0.5 cylinder is pretty mild astigmatism. More severe astigmatism will result in the dot looking like a streak, comma, football or some other less symmetrical shape.
With no astigmatism, I would not expect to see a circular disc with crisp edges in a mini reflex sight. This has to do with how close the diode (LED) is to the reflecting surface and how that surface has to be curved to reflect the diode so that it is focused at infinity.
The best way I've been able to tame the starburst is to turn the brightness down. If I dial it down two steps from the auto-adjust level, the dot bursts much less. The auto level is set to make the dot easy to find. The brightness can be adjusted manually and locked in, but I use the auto level for my carry optic so that it will be easy to find under various conditions. If I set it down two-levels manually, I can hit anything within 2.5 MOA so long as I am able to hold it steady or rest it.
If I use the factory adjustable rear sight and front ramp, I can use a particular tiny spot on the front sight to make small groups -- the gun's precision is there -- but I cannot be as accurate as with the reflex sight.
I tried to simulate worse astigmatism. First, I tried doubling-up my corrective lenses, but that didn't seem to work. Instead, because my astigmatism is vertically-oriented, I tried turning my corrective lens 90 degrees. I also tried looking through the correcting lens with the non-astigmatic eye. The results were disturbing to the image, but not so severely that the reflex sight would be unusable. I could only speculate that at some point beyond a 1.0 cylinder, I would begin to consider an alternative to reflex sights. I think if I had 2.0 cylinder in my dominant eye, I could still use reflex sights with corrective lenses, but I would have to consider that I might not have or be able to keep my corrective lenses on in some circumstances. While that would not disable my use of the sight at short ranges, it would diminish or eliminate any advantage gained from the reflex vs. standard sights.
Looking at a Trijicon slide-ride type mini-reflex, the 2.5 MOA dot is a starburst with either of my eyes. With the astigmatic eye, the burst is elongated vertically (the orientation of the astigmatism) so that it looks like a tiny octopus with legs hanging down. With lenses that correct the astigmatism, it looks like a round starburst.
0.5 cylinder is pretty mild astigmatism. More severe astigmatism will result in the dot looking like a streak, comma, football or some other less symmetrical shape.
With no astigmatism, I would not expect to see a circular disc with crisp edges in a mini reflex sight. This has to do with how close the diode (LED) is to the reflecting surface and how that surface has to be curved to reflect the diode so that it is focused at infinity.
The best way I've been able to tame the starburst is to turn the brightness down. If I dial it down two steps from the auto-adjust level, the dot bursts much less. The auto level is set to make the dot easy to find. The brightness can be adjusted manually and locked in, but I use the auto level for my carry optic so that it will be easy to find under various conditions. If I set it down two-levels manually, I can hit anything within 2.5 MOA so long as I am able to hold it steady or rest it.
If I use the factory adjustable rear sight and front ramp, I can use a particular tiny spot on the front sight to make small groups -- the gun's precision is there -- but I cannot be as accurate as with the reflex sight.
I tried to simulate worse astigmatism. First, I tried doubling-up my corrective lenses, but that didn't seem to work. Instead, because my astigmatism is vertically-oriented, I tried turning my corrective lens 90 degrees. I also tried looking through the correcting lens with the non-astigmatic eye. The results were disturbing to the image, but not so severely that the reflex sight would be unusable. I could only speculate that at some point beyond a 1.0 cylinder, I would begin to consider an alternative to reflex sights. I think if I had 2.0 cylinder in my dominant eye, I could still use reflex sights with corrective lenses, but I would have to consider that I might not have or be able to keep my corrective lenses on in some circumstances. While that would not disable my use of the sight at short ranges, it would diminish or eliminate any advantage gained from the reflex vs. standard sights.
If you have astigmatism, use corrective eyewear of the proper prescription. Now, you no longer have astigmatism. That said, protective eyewear is made of polycarbonate and this is one of the most distorted “optical” materials. Glass is the least distorted, but not usually used as protective eyewear. If you’re over 30y.o. you are in a race to see if you qualify for cataract surgery, or die first. Flare and glare are common symptoms of cataracts.
westernrover
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- May 4, 2018
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The other phenomenon at work here is diffraction. Even if you do not have astigmatism, you will see bright point light sources as bursts when diffraction occurs.
hoardingthemanual
Member
I have slight astigmatism and it causes the flare around the dot. I tested a prism scope and it was perfect.
These are the two solutions for me.....or just live with it like i do on my pistols.
doubleh
Member
I don't have astigmatism but my daughter does and prescription lenses take care of it for her. Her's is quite pronounced and has been since she was a kid but she can use a red dot.. Before cataract surgery I was having some trouble with red dots having a tail at about 120 degrees from the top. When the cataracts left so did any distortion of the dot. I don't know if it will work with astigmatisim but I found turning down the intensity of the dot did a lot to make it round.
conan32120
Member
I wear progressive lenses and parts of them give me the flare, other parts do not. You could just try an LPVO, worked for me
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