Should I not wear glasses when using scopes?

[SerenityNetworks]

Can focus adjustments and/or the wearing/not-wearing of glasses impact sighting?

I heard a comment a while back at the range that piqued my curiosity, but I didn't have the opportunity to follow up with the person that made the statement. The statement pertained to someone that wears glasses shooting the rifle of another that doesn't wear glasses. He said that wearing glasses will change the parallax and apparent position of the reticle. He also said changing the focus on a scope would alter the parallax and apparent position of the reticle. (In short, he was incensed that the person he was letting shoot his rifle had changed the focus on his scope.) The statements didn't make sense to me, but the gentleman seemed otherwise knowledgeable about bench shooting, so I thought I would follow up here.

I can't see how changing the focus on a scope would have any effect on anything other than focus. Am I missing something? Now throwing into the mix another lens (my glasses) is another story. The physics of optics are way beyond my knowledge base. In brief experimentation, I couldn't see where either focus adjustments or wearing/not-wearing glasses made any difference. But then again, I'm not a bench rest shooter and my marksmanship skills are very modest. The changes could well have been overshadowed by my lack of skill.

I normally shoot with one of three pairs of glasses on, but the correction for distance is very minor. That is, I could shoot fine without glasses (through a scope) if it were better to do so. It would just be a PIA to be popping them on and off to make notes, etc., so I'd rather leave my glasses on if it makes no difference.

I'd appreciate any guidance on this matter.

Thanks in advance,
Andrew

PS. Yes, I'd certainly wear zero correction safety glasses if I'm not wearing my Rx safety glasses.

 

[FoghornLeghorn]

I wear glasses whenever I shoot. That includes scoped rifles, and I've never had a problem.

Try it. If you shoot accurately, no problem.

 

[dahermit]

To be on the safe side, if you do not use "shooting glasses" when shooting, or you use prescription glasses when shooting, you should specify polycarbonate (safety glass) lenses from your eye doctor the next time you get your glasses changed.

 

[TXAZ]

I tried it both ways, I leave my glasses on with a scope. I don't seem to have the parallax problem you mentioned. It's a pain to me taking them on then off, particularly if I want a wider field of view quickly.

YMMV

 

[SerenityNetworks]

Prior to getting back to shooting, my primary hobby was R/C Aircraft. All my Rx glasses are polycarbonate 'safety' glasses and have been for years.

I've never noted a change in my POI if I change focus or if I shoot with prescription glasses on or off. But like I said, maybe my lack of precision is obscuring the change. (Right now I'm consistently shooting between 1.00 and 1.50 MOA.) Would someone that shoots 0.50 MOA notice a change? Or I am just wondering if there is an optics expert on the forum that can squash the matter with an expert statement.

Meanwhile, I'll keep shooting with my glasses. If there is an impact I can't see that it matters to me now. This was just a curiosity question.

Thanks again,
Andrew

PS. TXAZ, I like your signature.

 

[ScottRiqui]

I'd have to double-check my optics textbooks, but when you're using a rifle scope, you're not really looking *at* the target itself, but rather at an image of the target that's being projected by the various lenses in the scope.

As such, the part of the target that's covered by the intersection of the crosshairs is already determined by geometry of the lenses. So wearing or not wearing your glasses shouldn't change it, other than to make it clearer or fuzzier. Likewise with adjusting the focus control on the scope.

Imagine holding a pencil in front of a page of text. Whether you wear your glasses or not, the exact same words on the page will be obscured in either case.

 

[SerenityNetworks]

Thanks Scott. Your answer makes perfect sense.

What the gentleman was saying didn't seem correct to me. If change of focus had an impact then I would have expected it to be in bold red print in any scope's manual. I would expect the same with the use of glasses. If different glasses or different eyeglass positions (relative to the scope) had any impact then I would have expected to be alerted.

Anyway, thanks again,
Andrew

 

[Kreyzhorse]

Good answer Scott R.

 

[geetarman]

I used to take my glasses off when I used a scope. The range I use now requires glasses be on all the time.

I just refocused the crosshair. Everything else is the same. My binoculars and spotting scope both have provisions for users with glasses so you can always get a full field of view.

 

[hermannr]

If you are missing or changing point of impact, you may actually be shooting with the wrong eye. Ever check? Our oldest daughter is left handed and right eyed, our youngest is the opposite.

I wear my glasses when I use a scope and when I use iron sights. You do need to be conscious of the fact that the center of the lens of you glasses is ground slightly different that when you move out from the center.

You can also get contacts and shooting glasses then you don't have to move your glasses to compenasate for the curve of the grind.