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Posted: 11/21/2008 2:15:16 PM EDT
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Let me preface this post by saying that the Aimpoint CompM4 is a fantastic optic. I would recommend it to anyone. That being said, I have to admit that it may not be the right optic for me.
The basics: I have a Bushmaster M4A2 style carbine and have the scope mounted on an Aimpoint cantilever carry handle mount (from SWFA). I had to shim the mount to get it rock solid, but it does not move and I definitely trust it. My problem stems from bad eyesight. I am right-eye dominant, but I also have an astigmatism in that eye. The first thing I noticed when looking through the scope is that I am not able to see a defined "dot" as the point-of-aim. I see two dots...one bright and more defined, the other dimmer, and both diagonally opposed touching one another. Kind of like the "MasterCard" symbol on a diagonal. I hope my description makes sense. When I look through the scope with my left eye...perfect. I can clearly see the dot in the center and feel confident aiming. Sense I had trouble determining how to properly aim with my right eye, I decided to sight in the rifle left-handed (using my left eye). I was able to confidently zero in and shoot a 1" and a 1.5" group at 100 yards. Each group was four shots. I was very pleased to get that kind of group with a 1x scope and XM193 ammo. I then switched to right-handed shooting to see if I could get it to group well. I figured that if I can at least keep it under 2" at 100 yards, even with my bad eye, that was perfectly acceptable since I have no plans to use the gun past 200 yards. What I got was a group under 2", but 4" to the right and 1" high of the group shot left-handed! First I thought this was because I was simply aiming with the wrong "dot" in my vision. So I shot two more groups, aiming with each "dot" in my vision. The group moved a little when using the two dots, but not more than 2" (hence the 2MOA dot). Each group was still to the right by 4"-5"! I have been shooting for 20 years, and have two other scoped guns (M1A w/ Bushnell 3200, and Ruger77 w/ Leupold FX-II) and have never had point of impact change when shooting right vs. left handed. Both these guns I mention are sub MOA using standard plex reticles and I don't have any sight issues using these scopes with my right eye. I practice shooting from both sides regularly because I have had to take plenty of left-handed shots when hunting from a tree stand, so I like to be ready. I love the scope and the versatility it provides. It was a joy shooting it left-handed, so this was a very disappointing day for me. I intend to contact Aimpoint on Monday, but if it's just my poor eyesight I will probably be putting the scope up for sale on the EE. -J |
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As I have been sitting here thinking about this, there are a few idea that come to mind:
-Would canting the rifle slightly (very slightly) have this great of an effect on the point of impact? -When I co-witness the iron sights with the red dot, my range results are confirmed. With my left eye the dot is in the center of the front post. With the right, it is on the left third of the front sight. But wouldn't that imply parallax issues? -If the optic were not aligned to the bore on the horizontal plane (left to right), could this cause a parallax issue? The optic looks straight on the rifle to me, but it is a very short scope and a minor misalignment would be hard to tell. -Eyeball transplant... 
I hate that this is happening. I really like this scope. -J |
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I thought the idea behind the red dot system was the idea that you keep both eyes open, it is not meant to be used as a traditional rifle scope, is it? Please, someone correct me if I am wrong. I love mine!! You bring up a very good point. I admit I closed one eye much of the time I was shooting today. I tried shooting with both eyes open a few times, but have yet to get used to it. I didn't think that would effect POI, would it? Found this AFTER I got home today...duh: http://www.aimpoint.com/o.o.i.s/391 And no, I didn't RTFM. -J |
I too have had horrible results due to my eye sight(real bad astigma). I thought all red dots were suppose to look how i saw them. Are you wearing contact lenses? After a fresh eye exam(my grandpa is in the optomitrist, so I might have got away with something) I actually mentioned this. He said contacts, even the ones that fix astigma, can not do what eye glasses do. He gave me a prescription, and sure enough, that dot is Tiny! The prescription he gave me is Way to strong for close up, but has a power for far away. Another thing is before discovering all this, i had good luck with eotech dot. my normal sets of glasses do alot better that contacts that fix astigma. Pretty sad I am only23 and feel like a 60 year old 
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Get Lasik vision correction - most places offer no interest financing and can fix astigmatism. Sometimes....I had Lasik and still have astigmatism in my left eye. My right (dominant) is now 20/20 so it wasn't a complete failure. I wear glasses which correct the glare problem at night and while shooting. To the OP, I would try with glasses on and both eyes open before I got rid of the RDS. If that doesn't help than a x1.5 ACOG will probably be the best bet. |
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Based upon your description, there are two different optical issues going on. The first is the POI shift associated with eye dominance, and the second is your astigmatism. The good news is that both are quite easily accommodated!
As a matter of coincidence, I also happen to be an engineer who is right eye dominant, with astigmatism in that eye only, so hopefully this will be useful info to you. Since you know your eye dominance, presumably you have performed the simple test for same. For those who may not be familiar with one of the more common test methods, the individual should hold his hand out at arms length with the index finger pointed up like a sight post. With both eyes open use the fingertip to sight in on a fixed target about 25 feet away. Alternately close one eye and then the other without moving the finger. The eye for which the target stays on top of the fingertip is the dominant one, and the one where there is a POA shift is the non-dominant one. The amount of shift will give you a feel for the magnitude and orientation of the dominance. One shooting situation where this is very important for me is firing a tritium-sighted handgun with NV. For those not familiar with the characteristics of a NV monocular, anything inside of about 10 feet is out of focus when the objective is adjusted to "infinity". What this means is that one cannot effectively focus on the target and the handgun sights simultaneously with the same eye. I use the superimposition method whereby the target is observed through the monocular in front of the non-dominant eye, and view the handgun sights with the un-aided dominant eye; the brain processes the data into a combined image. The POI shift for me is about 4 inches left, and slightly high at a range of only 10-15 yards....yeah that much! Since I have practiced the technique, I know where to adjust my POA to get good hits. If you sight in your Aimpoint with both eyes open, there should not be a shift except when you utilize it only using your non-domiant eye. As far as the astigmatism, get some prescription glasses. My eyesight started deteriorating within the past few years [getting older sucks in some regards], and boy do a good set of glasses make all the difference in the world when shooting or driving at night. One can adjust the diopter on his optic to account for nearsightedness or farsightedness, but astigmatism is something that needs a different lens. Considering how much some people spend on firearms, optics, and ammo, an eye exam and a proper pair of glasses is comparatively inexpensive. |
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Thanks for all the responses. Let me answer questions one by one:
-I wear glasses only, no contact lenses. I tried them once but could never get used to them in my eyes, and since my hands are rough and somewhat calloused, I can't stand touching my eyes. Me<-Wuss. -Just had my eyes checked this year, always do it once every two years. I never skimp on glasses. My lenses alone are about $300 once I have them put on their super anti-glare and whatchamacallit coatings. I used to do Wal-Mart glasses, but learned my lesson. Plus I'm employed now so I can afford it. -I really don't want to get Lasik. Again, Me<-Wuss. I have a friend that was one of the 5% that had problems. Has been going back for the past two years (!) so they can gradually correct they're "mistake". In the mean time he has really only been able to see well out of one eye. I'll keep the glasses. Plaskon, I'll get in touch with you soon. I want to look for an alternative scope so I can buy it soon. I'll send a PM. Thanks, -J |
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My Aimpoint dot is slightly out of round for the same reasons, but not enough to cause me any problems.
In your case, obviously you're not happy with it. Have you tried looking through a Trijicon Tripower? I've heard some guys say that it does not cause problems with astigmatism, and the drawbacks the optic aren't that big of a problem for non-military use (short battery life, light leakage out of the fiber optic as seen through night-vision). If you got one, just make sure to get the new version... they're floating around for about $300, $350 like new if you keep your eyes open. |
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I feel your pain. I just bought an aimpoint today and it is the worst looking red dot I have ever used, at least looking through it in the house.
It has been a while since my last eye exam, but I haven't noticed any problems, and the last exam was 20/10. The dot looks like a diamond to me with either eye. When using a magnifier it looks like 3 dots side by side making a hash. I'll shoot it tomorrow and see what results I can get. |
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This one is easy. You are right eye dominant. You are BACing the Aimpoint when shooting left handed because you are so extremely right eye dominant. Close the right eye when shooting left handed and the shift will go away. If it does not then you are actually left eye dominant and if you close the left eye when shooting your shift will go away (and you would need to rezero).
If neither of these is the issue you have a tropia, also known as gotch eye or sometimes crosseyed. Any optic will do this if it allows a unified FOV for your brain to merge if you have this condition. |
i can barely do that with a magnified optic 
i wear glasses. i'm right eye dominant, left handed. i shoot pistols and rifles left handed, use my dominant eye for pistols and left eye for rifles. sounds messed up, but so far i've been lucky and never had any problems doing so. anyways, i have astigmatism also, and the dot might not appear perfectly round or distinct. when sighting in an aimpoint, i find that it helps to flip up my rear BUIS and look through the small aperture - it makes the dot clearer. it doesn't change the POI when you flip it down. doesn't solve your POI problem but it might make the dot more 'round' for you. try it and see if it makes a difference. |
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Wow, didn't expect this to get ugly, but not surprised. Seems like there's a prevailing attitude amongst firearm enthusiasts to treat everyone they come in contact with like they're stupid. Being a teacher I don't like to treat people that way, because they just stop listening to you once you do.
Sorry if you guys think I'm lying to you if I say I shot a 1" group at 100yds with an Aimpoint. Not sure what you think I have to profit by that. Besides I was shooting from a bench off sandbags, so that just tells me it's a good scope and is mounted well. For those of you nearby and interested (central NC) I could teach you, I'm an NRA certified rifle and pistol instructor. Harv24, just let me know if you'll be in the area, and we can go to the range. I'll teach you everything I was taught by those better than me, which is the wonderful thing about instruction...passing it on. Also, for those thinking I somehow still haven't figured out which is my dominant eye...I have. It's my right, now let's move on. DevL - I actually was closing my non-shooting eye while using the scope, both right and left handed. That was my fault for not reading up on how to properly use the scope before going to the range. militarymoron - Looking through the small aperture of the rear sight does seem to help some, thanks. However I would rather not have to rely on this technique to be able to use my optic. I will be calling Aimpoint Monday to see what they say, maybe they have some suggestions. If not, then on eBay it will go. -J |
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DevL - I actually was closing my non-shooting eye while using the scope, both right and left handed. That was my fault for not reading up on how to properly use the scope before going to the range. I did the same thing when I first got my aimpoint and it had me greatly disappointed. It was such a huge bloom, I couldn't figure out how anyone used the thing. Once I stopped using it like I do other scopes, and just kept both eyes open and shot without thinking about the dot, it went away completely and is a non issue. |
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Geez Harv. Fortunately you (an apparently FedDC by omission) have no experience in this- have no training- and have no clue.  Harv simply asked if I could teach him to do that (albeit in a sarcastic way). My answer was yes (in a non-sarcastic way). Why does that warrant this response? |
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Because you don't know Harv- and I do.
Because you don't know his background, experience and expertise. And I do. I don't know your background, except for those nra certs you posted. But i know Harv, and FedDC. I also have a fairly good idea of abilities, capabilities and experience. So, i can have fun with Harv- and FedDc. |
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Because you don't know Harv- and I do. Because you don't know his background, experience and expertise. And I do. I don't know your background, except for those nra certs you posted. But i know Harv, and FedDC. I also have a fairly good idea of abilities, capabilities and experience. So, i can have fun with Harv- and FedDc. Understood. Well, if you are in VA, then you may not be that far away from me (I'm in Raleigh, NC) so if you're interested I would love to have an opportunity to get together and shoot with other AR15.com members like yourself. That way we can all get to know one another. Let me know if that sounds like a good idea. -J |
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militarymoron - Looking through the small aperture of the rear sight does seem to help some, thanks. However I would rather not have to rely on this technique to be able to use my optic. i only do this when sighting it in, and on occasion for longer distance shots. normally, it's flipped down. |
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militarymoron - Looking through the small aperture of the rear sight does seem to help some, thanks. However I would rather not have to rely on this technique to be able to use my optic. i only do this when sighting it in, and on occasion for longer distance shots. normally, it's flipped down. Good point. I'll give it a try it next time I'm at the range (hopefully this Wednesday). -J |
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You might want to try a Leupold CQ/T it has a rear ajustable eye peice,very clear glass and 1 to three magnification. Not for everybody ,but it dose it for me ! I'm trying to stick with something that's mountable on a gooseneck carry handle mount. Something with LER. |
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Try what I tried.
http://www.ar15.com/forums/topic.html?b=3&f=18&t=408157 I love my M4s even though it's my eyes that are the problem. I'll get the eyes checked out and if that doesn help with the contacts I'll get the eye glass prescription updated and try with them. If that works then I'll shoot with eye glasses. If it doesn't I'll live with it. |
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Have you tried the 2MOA dot ? If anyone is curious, The 2MOA and 4MOA dots both look like blurry crescents because of my astigmatism. Hence why I own no Aimpoints. Well, what do you own? Maybe something you're using will work for me. -J He owns irons because I can't convince him to buy an ACOG. |
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I have the same problem with Aimpoints. It's always a lot worse indoors- out of sunlight.
A few people have had major success using a Killflash filter on their Aimpoints. I've never tried it, but my problem isn't too bad(since I mainly shoot outside). Just another consideration for you. |
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I have the same problem with Aimpoints. It's always a lot worse indoors- out of sunlight. A few people have had major success using a Killflash filter on their Aimpoints. I've never tried it, but my problem isn't too bad(since I mainly shoot outside). Just another consideration for you. That's a very good point. I have noticed it is easier to see in brighter outside light, especially when you dim the dot a bit. I have a killflash for it, but wasn't using it when I sighted in. I will try that this week. Thanks. -Jim |
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I have the same problem with Aimpoints. It's always a lot worse indoors- out of sunlight. A few people have had major success using a Killflash filter on their Aimpoints. I've never tried it, but my problem isn't too bad(since I mainly shoot outside). Just another consideration for you. That's a very good point. I have noticed it is easier to see in brighter outside light, especially when you dim the dot a bit. I have a killflash for it, but wasn't using it when I sighted in. I will try that this week. Thanks. -Jim Good luck. |
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