The Accurate Reloading Forums
Prescription Glasses When Sighting In
04 October 2012, 00:59
LJSPrescription Glasses When Sighting In
I recently got a new prescription for my eye glasses. I went to the range this morning to shoot 3 guns that I use regularly and I wore my new glasses. All rifles are good shooters with nothing changed on them. The loads are the same and the scopes unchanged. All three were erratic shooting with two bullet holes close together and two bullet holes a couple inches left or right. A good friend tells me he always sights his guns with non prescription glasses making the optical correction with the scope. Has anyone else had this problem shooting with prescription glasses?

04 October 2012, 01:22
LuckyduckerThe only time I have needed to shoot without my corrective lens glasses is with iron sights. I don't have any trouble looking through a scope with my glasses on.
Dennis
Life member NRA
05 October 2012, 06:33
Sagebrush BurnsIf you're going to wear the glasses when you're hunting, you need to wear them when you sight in.
05 October 2012, 08:42
sambarman338Yes, I can't see any reason why using your corrective lenses would cause that problem but, even if they did, you need to find some way to live with it.
Maybe your ocular-housing focus was set up without glasses and is giving some kind of alternative parallax when you put them on. So, the reticle focus should be reset with corrective glasses on.
To tease out SB's terse response: you would be right behind the 8-ball if you had to whip off the specs every time you wanted to shoot at game. In my case I'd be blind as a bat beyond the scope field and without sunnies, too.
05 October 2012, 16:51
LJSI was told the curvature of the lens varies and if you do not look through your eyeglasses at the same point everytime the point of impact will move slightly. I am talking about guns that I shot 3/4 inch groups before that are now having a separation with two bullets touching and two others touching but an inch apart.
My question pertains to sighting in the gun not hunting situations. Why does it matter if you wear your glasses or do not when sighting in? You can make the needed optical adjustment with the scope to clearly see the target.
SB should run for president. We need that kind of simplification in government.

12 October 2012, 11:25
sambarman338I don't suppose altering the ocular focus after sighting in would change your point of impact - but it might.
In any case, if wearing glasses causes these problems when zeroing, why would they not do the same when you were hunting? I don't suppose the problem could suddenly be parallax in all three scopes but cannot see for the life of me how the prescription specs could do this, since they won't change the image coming out of the ocular lens.
Have you refocused the scope reticles with your glasses on and then taken the rifles back to the range?
24 October 2012, 11:00
dan_ozI'm no optometrist, but maybe you aren't looking through the sweet spot of your glasses' lens when you are aiming. If you have a high correction/astigmatism and your head position is such that you aren't looking through the centre of the lens then maybe you are getting some distortion.
Specialised shooting glasses for target shooting are adjustable, allowing the corrective lens to be moved so that it is directly in front of the eye when in aiming position, to give the sharpest/best view of teh sights. They aren't going to be very practicable for hunting, but maybe you could have a look at your head position instead - do you bring the rifle up to align with your eye while holding your head upright? Or do you drop your face forward onto the comb of your stock and look out through the top of your specs? Or tip your head to the side perhaps? You also might have a word to your optometrist of course, to see what they might have to offer.
HTH
26 October 2012, 05:43
D Humbargerquote:
Originally posted by LJS:
I was told the curvature of the lens varies and if you do not look through your eyeglasses at the same point everytime the point of impact will move slightly.
You are absolutly correct.
Doug Humbarger
NRA Life member
Tonkin Gulf Yacht Club 72'73.
Yankee Station
Try to look unimportant. Your enemy might be low on ammo.
26 October 2012, 12:14
mike7mm08Just give yourself some time to adjust to the new glasses. I have had similar problems. Not just with scopes but with seeing in general when I get new glasses. With the glasses I just got recently I thought the script was wrong the edges of my vision seemed fuzzy. Turns out the lenses are smaller and have a smaller area of optimal vision. Took a bit but my eyes have adjusted and now focus in on area of optimal vision of the lenses.I have to make a real effort to find the area of the lenses that are not perfect as my eyes want to stay focused on the center of the lenses.Your eye will develop muscle memory to look through the new glasses and focus in on the area of optimal vision. Once this happens you should be looking through the glasses the same all the time and in turn your scope the same. Still might have to make adjustments. But everything should tighten up group wise.
05 November 2012, 22:48
ClemAre you wearing bi-focal or progressive lenses? Try your old glasses and see if it improves.
06 November 2012, 02:47
LJSI went back to my older glasses with larger lens and the groups tightened right back to before. I talked to a pal who was involved with the sniper group at Fort Benning and there is actually a spec for this kind of thing. He suggested raising the overall height of the rifle when at the bench and it works. Doing that seemed to stop me from looking through the top of the lens.
07 November 2012, 17:41
sambarman338quote:
Originally posted by LJS:
I went back to my older glasses with larger lens and the groups tightened right back to before. I talked to a pal who was involved with the sniper group at Fort Benning and there is actually a spec for this kind of thing. He suggested raising the overall height of the rifle when at the bench and it works. Doing that seemed to stop me from looking through the top of the lens.
It's interesting to see your hunch backed up like that, LJS, but raising the rifle height on the bench will only help if it brings it into the same sight situation you'll experience in the field. Using a bipod at the bench and when hunting could help but, when shooting prone in the field, I think you'd find yourself back in that situation of looking through the top of your lenses. Therefore, you might be limited to the other positions and high rests, and taking extra care when shooting uphill.
I've got multifocal specs at the moment that have slightly less long-distance vision than I'd like. When shooting, however, I'm happy that my natural stance always leaves me looking through the top third of the lens.