Optic Plan B: Astigmatism

[firstsoundhere]

You could also try to go with an eotech. I have the same starburst effect shooting with my dominant eye with a PA red dot, but my Eotech is a clear dot even on higher power settings.

[Hammar]

I have found that eotech's and c-mores are less likely to be a problem than aimpoints with this issue. That is to me, and I have no idea why.

[firstsoundhere]

Did some searching, but couldn't find conclusive holo vs. red dot which is better for astigmatism: http://www.calguns.net/calgunforum/s...d.php?t=340115

My experience could also be the difference between a $500 holo and a $100 red dot.

[Hmac]

Did some searching, but couldn't find conclusive holo vs. red dot which is better for astigmatism: http://www.calguns.net/calgunforum/s...d.php?t=340115

My experience could also be the difference between a $500 holo and a $100 red dot.

Why would there be a difference. Astigmatism interferes with your ability to see an object in focus. Your ability to focus on a holgraphic dot 10 inches in front of your face vs your ability to focus on any other red dot 10 inches in front of your face?

[shootist~]

Why would there be a difference. Astigmatism interferes with your ability to see an object in focus. Your ability to focus on a holgraphic dot 10 inches in front of your face vs your ability to focus on any other red dot 10 inches in front of your face?

SWAG is maybe one dot is already more in (or out) of focus than the other. I only use Aimpoint red dots (battery life thing), but I've noticed it as well a couple of times when picking up someone's Eotech.

I also see a noticeable favorability with my Micro Aimpoint Vs my Comp ML3 for some reason. Both 4ish MOA dot size.

I see grapes w/o glasses, and a comma with glasses - whether it's my standard glasses with stigmatization correction or my prescription (distance only) DeCott shooting glasses, without that correction..

[Ick]

We need an optometrist to come in here and explain what exactly the scope of the problem is.

Even a guy with perfect eyesight will experience the effect of bending light from heated air/moisture on a sunny day...effectively what you see doesn't match reality.... this is the same type of thing that happens to me with astigmatism.

Furthermore, just like a guy seeing the desert mirage, there is no 100% foolproof way to "correct" with a lens or device what a soldier sees through a mirage to bend the light back into focus. Same thing with my faulty eyes.

Here is a one dimensional graphical illustration of astigmatism:



As you can imagine, astigmatism isn't a one dimensional problem... so that chart doesn't really show the full scope of the problem. Add to that having to line-up multiple lenses in your optic, the lens in your eye, corrective glasses, AND bent light due to astigmatism... you get a guy that literally can't shoot straight.

You can correct my eyesight enough to function, but to thread a needle at 300 meters just isn't going to happen.

[Hmac]

The reticle on Aimpoints and Eotechs is collimated to be in focus roughly at infinty. If you get your eyes to focus on the dot instead of the target, you will get pixelation and blooming on the Eotech reticle, and weird shapes on the Aimpoint dot.

[Hmac]

We need an optometrist to come in here and explain what exactly the scope of the problem is.

Even a guy with perfect eyesight will experience the effect of bending light from heated air/moisture on a sunny day...effectively what you see doesn't match reality.... this is the same type of thing that happens to me with astigmatism.

Furthermore, just like a guy seeing the desert mirage, there is no 100% foolproof way to "correct" with a lens or device what a soldier sees through a mirage to bend the light back into focus. Same thing with my faulty eyes.

Here is a one dimensional graphical illustration of astigmatism:



As you can imagine, astigmatism isn't a one dimensional problem... so that chart doesn't really show the full scope of the problem. Add to that having to line-up multiple lenses in your optic, the lens in your eye, corrective glasses, AND bent light due to astigmatism... you get a guy that literally can't shoot straight.

You can correct my eyesight enough to function, but to thread a needle at 300 meters just isn't going to happen.

It gets complicated when a person gets to an age where presbyopia (about age 40) begins to insert itself in the equation of near-sightedness, especially true with near-sightedness and astigmatism. That makes for a rather challenging prescription. The distant vision prescription might be well corrected in both axes, but when you get into the near-vision correction, it might not be ground as well, or your optometrist didn't measure cylinder and axis correctly (or at all) in the near prescription, or the optical lab (especially true of budget optical labs) might have ignored astigmatism correction completely in the transition zone of your no-line bifocals, or trifocals.

Astigmatism is completely correctable with a proper prescription, but it requires that your optometrist be skilled in managing both axes (cylinder and axis) to correct for it, then that the optical lab that's grinding your lenses also be up to snuff. The two-for-one deals at Walmart Vision Center or the grind-your-lens-while-you-wait are horrible places to get glasses for someone who has any significant astigmatism.

[Ick]

Awesome breakdown, thanks. By the way, I was told that once I have cataract surgery some of these problems improve greatly when they replace the lens.

I plan to win every 3 gun shoot on the east-coast after that happens, so some of you guys might as well start looking for a replacement hobby right away...

[Hmac]

Awesome breakdown, thanks. By the way, I was told that once I have cataract surgery some of these problems improve greatly when they replace the lens.

Maybe, except that astigmatism is more often related to irregularity in the cornea, not the lens.