When I first "graduated" from the AN/PVS-7 to the AN/PVS-14, like most, my "natural" instinct, like many was to start with the monocular over my dominant eye.

Then I "got wise," and learned from those who had more experience than I, and started running my NVD over my non-dominant eye. For a long time, I assumed that running your monocular non-dom was a sign of being "in the know." Later on, I "graduated" again to binos, and, in the interests of full disclosure, have never really looked back. I'm not someone who prefers a monocular to binoculars under any circumstances, though for a variety of reasons, I try to maintain my "currency" with the use of monoculars, as that is what the vast majority of folks, both military and civilian are using.

With that, I have since come back around to preferring the dominant eye for a standard monocular (fusion systems like the AN/PSQ-20 are a different matter, in large part due to their form factor).

In part, this has to do with my increased use of high-rise optics and passive engagement for which I've become something of an evangelist, but not entirely.

Somewhat related--pistol mounted RDS too (in and of itself, a "passive" method of NV aiming) has played a part in that as has already been pointed out, but again, while a compelling reason, it is still not the whole reason.

Rather, it has more to do with the way the brain and eyes work:

Getting things out of the way, humans use vision as their primary sense, that is why NV is such a potent technology, it allows you to see, and see better when others cannot. With that, most people have a fairly strong eye dominance, wherein the majority of sensory information comes from their dominant eye--the non-dominant eye primarily provides depth perception, supplemental information, and peripheral vision, this can be easily seen when using iron sights with both eyes open and focusing on the front sight--as you focus on the front sight and align it with your target, both of your eyes perceive it as aligned. Close your non-dominant eye, and your front sight will remain aligned with the target. Close your dominant eye, and you'll be nowhere close.

When applied to the use of a monocular, and given that sight is your primary sense and your brain is already conditioned to receive the majority of its information about the environment from your dominant eye, if it's dark enough to use/need night vision, why would you not want your dominant eye to see better?

Your non-dominant/dark adapted eye will still give you the supplemental information that it's always giving you, but you will be getting the majority of your sensory information from your dominant eye, as usual, and as desired--the discussion elsewhere in this subforum about "do specs really matter" has some bearing here, too--many people's non-dominant eyes are in fact, a little "worse" than their dominant eyes. Again, if it's dark enough to need night vision, why wouldn't you want your best eye to be getting the best information?

"But what about mixed light or if the lights go on?"

The logic behind putting your NV monocular over your non-dominant eye is usually something along the lines of the idea that somehow your natural eye dominance combined with the NV will "even out," that your dominant eye can see better in the dark than your non-dominant eye, and will somehow provide you "better" information while unaided, while your non-dominant eye "needs the boost" when conditions are darker.

This "compromise" may sound good in theory, but in practice, I've become increasingly skeptical that it's true.

First of all, while it's not something I recommend you try often, especially with personally owned NVDs--you can still see through your monocular in a brightly lit room. Moreover, you can still aim with an IR laser or even passively through your optic with the lights on. Is it good for your tube? No. But if and when that time comes, your tube life is probably the least of your worries.

Second, when conditions are bright enough for you to see without the NV aid, then your brain will automatically "switch" to the eye that can see better, i.e., your non-dominant eye, in fact, the practice of using your monocular over your non-dominant eye "proves" this, when it's dark enough, you'll automatically use the eye that can see better, meaning you're not going to be missing much if the lights suddenly come on, or if you're in a mixed light environment that's bright enough that your non-dominant eye is getting better information than your dominant eye.

Furthermore, in a lit environment, looking through your monocular is not dissimilar from looking through a unity powered RDS--yes, the housing of the monocular is "technically" obstructing your dominant eye's vision, but if you keep both eyes open, the housing "disappears," as the supplementary information is filled in by your non-dominant eye, the effect is less a "being blind in one eye," as something of a stereoscope or old-school 3-D glasses, where you're seeing everything a little "greenish" (or slightly "bluish," but even less noticeable if you're using WP tubes) but your brain is already collating the information provided by your two eyes, so your primary sensory input is that of "true" color.

The net result is that you don't really see any "worse" in a mixed light/bright light situation with your monocular over your dominant eye, but you see better in "true" dark by not fighting your natural instinct to want to use your dominant eye as your primary visual input versus trying to "split the difference" between your dominant and non-dominant eye and fighting your own brain.

The crux the issue again goes to: if it's dark enough to use NV, why wouldn't you want to see as well as you can, rather than trying to compromise between your better and worse eye? Your non-dominant eye will still give you all the supplemental information it's used to giving you, while your dominant eye is getting the NV "assist" so you can see better, without having to fight your brain to use your primary sense, and if it gets bright enough, your brain will do all the work for you, and in the critical moment, you probably won't even notice that the lights went on, after which point you can make the decision as to whether you're going to go back into the dark, or if it's time to flip the NODs up. Plus, you can take advantage of passive NV aiming capabilities, as well as maintaining day/night consistency with your pistol presentation if you're using an RDS on your pistol.

~Augee

I must say that I will save Augee's response and use it as the best analysis of the dominant/non-dominant eye dilemma that I've seen.  I prefer to use monoculars on my slightly dominant eye but my personal preference should be ignored due to my ambidextrous personality.

Non dominant eye for me.  I started with a dominant eye and eye cup with gain cranked way up.  Ripped that garbage off.  Now run no eye cup, non dominant eye, low gain.

Low gain keeps my eye from tiring out as well, and feels more natural in terms of how I see things.  More "seeing with night vision" and less "looking through a tube."  Also helps get the thermal optic up to my eye fast without flipping the 14 up.

Not sure what you're asking--are you asking about offset issues?

Adjustment ranges?

I boresight/zero my lasers to high-rise optics the same way I would with absolute cowitness or lower-1/3 cowitness. Again, the laser is not, at least to me, a precision aiming solution, and I have not ever noticed a practical difference between high-rise and more traditionally mounted optics, though to be fair, I've never sat down and shot groups to see "exactly" what the shift was, if any.

~Augee

For all intents and purposes, yes, just align the dot with your day sight at your desired range, and you should more or less be good to go.

Even if your day sight is zeroed to a different range than you use at night, you should generally be close enough to your day sight offsets as you’re just trying to match the direct LOS of your day sight’s POA, not trying to intersect your bullet’s arc at any given range(s), therefore, the further out you zero your IR laser, the more you “cancel out” your mechanical offsets.

You’re correct, however, that at closer ranges, your laser dot will be offset slightly, but what you will see through the optic is not your offset relative to your bore (e.g., high right with a 12 o’clock mounted ATPIAL), but rather your offset relative to your reticle’s direct LOS, so up close with the same configuration, your laser dot will be low right, with the offset shrinkingp until you reach the distance at which you coaligned them. What you will see past your point of convergence may depend on the range at which you coaligned the laser, the laser’s power, the size of your dot/reticle, and beam divergence, but yes, once they cross, your day sight’s direct LOS and your laser POA will begin to move away from each other in the opposite direction, but remember, you will still need to use your appropriate vertical offsets for the range at which you zeroed your day sight.

It sounds/reads more complicated than it is.

~Augee