For OP:
I assume you are near-sighted. I’m not sure what I say below applies towards our far-sighted brethren.
I don’t think a greater eyebox is going to solve your diopter readjusting issue, but it will solve some other issues. See below.
For
@wjm308:
Ok, good to know. Thanks for answering. What follows is some info that may help people understand the unique issues high-rx eyeglass and contact wearers have (specifically extreme near-sightedness).
I think many high-prescription near-sighted eyeglass wearers have more problems with eyebox than the general population. I know I do. And people with perfect eyes (or even “normal” bad eyes) tend to suggest fixes that help people like themselves. Which is totally normal, of course, but may not help the high-rx eyeglasses wearer.
I have even worse eyes than the OP (-10 to -12), and a generous eyebox is
the most important thing I look for in a scope. I usually wear glasses, but I’m starting to test out contacts to see if that makes scope-viewing a little easier. Initial tests seem to confirm my guess.
Diopter issues
As the OP alludes to, scope diopter settings (and rx power) change as one switches between near-sighted glasses and contacts. I don’t believe eyebox differences between scopes are going to change that fact. In other words, you’ll have to change diopter settings between glasses and contacts no matter the scope.
High RX problem #1
My ophthalmologist confirmed that at my Rx, there is a significant difference between the image size projected on my retina between glasses and contacts. When I switch between them, it takes a few minutes for my brain to readjust. Almost like a mini-vertigo effect.
I’m not sure how “image projection” plays into the problem, but I suspect it does. Essentially, with high-rx near-sighted glasses, it’s as though you are sitting in a dark room away from the TV, and with contacts, you are sitting right up close to the TV, IMAX theater-style. It’s hard to explain, but for an example take some binoculars and look through them the wrong way. That’s sort of the effect I’m talking about. Somehow, optically, this projection effect narrows a scope’s perceived eyebox.
High RX problem #2: optical center/focus point of glasses
I do know people have difficulty looking through the optical center of one’s glasses when behind a scope, and high-rx makes this worse because as one looks through a high-rx lens, there’s a greater relative difference in image quality as you look away from the focus point as compared to low-rx.
This due to how your head is positioned behind a typical rifle and is greatly exacerbated by super low rings, which force the head at an angle away from the perpendicular plane to the scope. Use high rings.
Regardless, there’s going to be some compromise in this area when behind a scope unless you have a special set of shooting glasses made with the focus point more towards the upper left (in a right-eye dominate/right-handed person).
High RX problem #3
Another thing people with high rx near-sightedness tend to have is lots of “
floaters”, which are more noticeable the higher the mag you are on the scope (probably because of relative size differences between floater and image). One has to “flick” them away with a quick movement of the eye, back and forth. I’ve had them since youth, and they tend to accumulate through the years (I’m 50).
All that “flicking” tends to also slightly move your head around, and the more eyebox the less re-centering of the head one has to do.
High RX problem #4: down the road – cataracts and retina detachment
Ok, won’t go into this because the effects of cataracts and one’s retina peeling off are pretty obvious. In the last month I found out I have a slight cataract in each eye, just like my dad did at my age. Wheeeeee!
