Prolonged blurry vision in non-dominant/non-scope eye? Is my focus off?

[dms416]

Just got a new NF 4-16x42 ATACR a few weeks ago and went out to zero on a rifle. I had it all mounted up and set the focus/eye piece to what I thought was correct (mostly used to the Euro style diopter and not the locking).

After I zeroed, I was doing some work taking some shots at distance and spent a good 20+ minutes straight on scope just watching mirage and wind between shots. I've been on scope for prolonged periods of time before and never had significant vision issues getting off scope.

When I got off scope, vision in my left eye was extremely blurry (I shoot both eyes open). Like I couldn't focus or decipher wording/lettering clearly on my ammo box. It freaked me the fuck out. It slowly improved and about 30 minutes later, everything was back to normal.
NOTE: Have not had this happen in 25+ years of shooting with optics.

Ideas?
Improper scope focus and sympathetic compensation?
Dehydrated?
Getting old?

 

[IronicTwitch]

Derecho really spiked allergies for people this fall and into early winter. My eyes are very sensitive to airborne dust and stuff. I use eye drops ("Pataday") and I've been much better since.

Mine was close up staring at my phone and looked up and couldn't read the 2" digital clock. Freaky. I'm only 39 and had Lasik when I was 30.

 

[slowworm]

When did you last have an eye exam? Might just be age related or allergy related but might be a symptom of something more serious going on.

Don‘t take chances with eyesight.

 

[dms416]

When did you last have an eye exam? Might just be age related or allergy related but might be a symptom of something more serious going on.

Don‘t take chances with eyesight.

Very regularly since my Lasik this past June...at the prescribed intervals.

Focus shift has slowed noticeably (i.e looking at a phone/book too long and looking up at a distance), but this was several minutes.

 

[Near miss]

I am 27 and had this same symptom when I was starting shooting around 7 years ago. I did find it interesting too, but though that it was just from the raw concentration I put on to the glass view as I was originally left eye dominant, training with my right eye. I would sometimes just look through the lens for some period of time to get the shift happen and then stay with it a while.

Back then I shot quite short distances with a scoped air rifle, around 20 yds.

I since then got to a 50m range and do not think I had it there once.

I would definitely readjust the scope eye-piece / reticle / diopter and ofc recheck parallax after that. I was a bit clueless about those back then.

 

[clcustom1911]

Your diopter may be set incorrectly and this is causing your muscles that pull on the lenses in your eyes to work overtime. Doing this over the course of several hours causes fatigue in those muscles and consequently, blurred vision once you are off the scope. Blurry vision continues because your eye muscles need to relax from all the work they were doing. Just like your skeletal muscles need to relax during a workout to get their strength back between sets of weight lifting.

Read this thread:

Rifle Scopes - Setting up a FFP rifle scope - A simple PSA on Diopters

bohemr13 X96 MONTHS Premium Member First Sergeant Rating: 3.6/5 this site 7824 posts this site Setting up a FFP rifle scope - A simple PSA on Diopters 03/02/2015 Last edited 03/03/2015 by bohemr13 (9 votes) I recently had a somewhat disgruntled customer return a scope because he complained of...

www.snipershide.com

Once your diopter is set according to that thread, go to the range and put a target at 100 yards. Set your parallax to where the target is crystal clear. If your diopter is 100% correct, you should be able to see both the reticle AND target WITHOUT needing to shift focus between the two with your eye. If the reticle and target are not clear at the same time, while keeping everything aimed on target, look away for a few seconds and make a small adjustment, either + or - to your diopter. Once adjustment is made look through the scope. Better? Worse? Keep making small adjustments until you can see both the reticle and target in sharp focus.

Once I figured that process out, I found once the diopter is set correctly, the parallax yardage lines actually corresponded properly to actual yardage in the scope I was using at the time.

 

[Jackalope]

Good post above. I recently got a new prescription and the optometrist wasn’t fully able to correct my left eye. My brain had a really hard time adjusting to it and it took me hours of messing with my NX-8 over a couple weeks to get the diopter right.

 

[dms416]

Your diopter may be set incorrectly and this is causing your muscles that pull on the lenses in your eyes to work overtime. Doing this over the course of several hours causes fatigue in those muscles and consequently, blurred vision once you are off the scope. Blurry vision continues because your eye muscles need to relax from all the work they were doing. Just like your skeletal muscles need to relax during a workout to get their strength back between sets of weight lifting.

Read this thread:

Rifle Scopes - Setting up a FFP rifle scope - A simple PSA on Diopters

bohemr13 X96 MONTHS Premium Member First Sergeant Rating: 3.6/5 this site 7824 posts this site Setting up a FFP rifle scope - A simple PSA on Diopters 03/02/2015 Last edited 03/03/2015 by bohemr13 (9 votes) I recently had a somewhat disgruntled customer return a scope because he complained of...

www.snipershide.com

Once your diopter is set according to that thread, go to the range and put a target at 100 yards. Set your parallax to where the target is crystal clear. If your diopter is 100% correct, you should be able to see both the reticle AND target WITHOUT needing to shift focus between the two with your eye. If the reticle and target are not clear at the same time, while keeping everything aimed on target, look away for a few seconds and make a small adjustment, either + or - to your diopter. Once adjustment is made look through the scope. Better? Worse? Keep making small adjustments until you can see both the reticle and target in sharp focus.

Once I figured that process out, I found once the diopter is set correctly, the parallax yardage lines actually corresponded properly to actual yardage in the scope I was using at the time.

This makes the most sense to me in having an unfamiliar brand that’s not correctly adjusted.

 

[Dunraven]

first place to start would be focusing your reticle, as already mentioned. make sure you know how to do this properly. then, when was your last eye exam? from a retired OD.