Eye prescription change and parallax question

[SqrlHntr]

Howdy all. Will a slight change in an eye prescription have an effect on parallax and ranging or am I nuts? ( rhetorical question, all airgunners are nuts on some level) Recently I went to the eye doctor and had an eye exam. It was a required visit to get contacts even though my prescription hasnt budged in years. To my surprise my shooting eye was weak by a quarter point. Not enough for me to notice it really, been just fine wearing contacts and using reading glasses. Doctor said my left eye was compensating for it. New multifocal contacts ( ditched the readers) and went a shooting. ( fwiw they are amazing, best vision ive ever had) BUT Apparently my parallax ranged and marked marked scopes need to be adjusted now. Reticle obviously needs to be focused again from the multifocal lenses and ditching the readers, but the quarter point prescription change seems to have also offset my distance markings as well, not much, maybe a couple of yards. Anyone else experienced this or similar?


The rifle still shoots the same too, no chrony drop, same ammo, same ballistics, basically the same weather too. I confirmed drop to 55 yds and nothing changed with the rifle. I can say there must have been eye strain i never noticed, its much easier to shoot long sessions now and practicing with open sights is much easier too. I can speculate to why only my shooting eye changed, maybe staring at an ATN scope screen for hours at night or just age, but thats not the point or the question here. Has anyone else noticed a parallax ranging shift or offset from a eye prescription change? Thanks in advance and thanks for reading. 

 

[Eaglehorn]

A quarter is not a significant change in your prescription, but comparing it with your scope markings might make the changes more noticeable. If it was uncorrected astigmatism then that might explain it too. You're only going to see changes in your parallax or reticle if your previous prescription was not accurate at the time you made your markings. In your case, the extra power in your old lens might have shifted the focal point behind your retina. This is what would cause your eye to work harder to focus on what you're looking at (if you're presbyopic then that causes additional difficulty with your eye doing that type of work). I.e., a slight shift in your reticle and parallax is definitely possible but would probably only be noticeable if you had marked the exact location of where you had them previously.

 

[TXPlinker]

Most definitely!! Say before your scrip change you were seeing something clearly at 18 yards that most people see clearly at 20 yards. Now you see something clearly at 20 yards instead of 18 yards, so your marks will be 2 yards off. (just an example). So time to redo your marks. 

 

[gvlasak]

Don't forget that you look through the upper corner of your lens when you're looking for a scope. The actual correction that you have is in more of the center of the lens

 

[Exitpupil]

" Reticle obviously needs to be focused again" Move it and it changes ranging calibration.

 

[badammo]

I found that I can't hit the broad side of a barn with my glasses on. All my scopes are setup for no glasses. Since you have contacts taking them out isn't a realistic option. The extra lenses do cause trouble.

 

[blucrsr]

I set everything up while wearing my contacts. When I switched over to my glasses things were much worse.