Can someone help me figure this out? Just here recently(past couple of years) my vision is starting to deteriorate, just up close, say within 15" and closer, having to wear reading glasses for the newspaper and what not. It's been so hot for so long here in Texas that I have not shot much for several months, but went out this weekend and something has happened, groups opened up quite a bit, started trying to diagnose what happened, well all checked out good, what I found was parallax, the POI moved quite a bit 1" or more when I moved my head around looking through the scope, after I focused it, I dialed the parallax out where the POI did not move at all but the target was out of focus, groups tightened up, focused the target back in crystal clear, parallax back, groups opened up again. So I got another rifle out with basically the same scope, same problem, got out another rifle with a diffrent brand of scope, when focused at 100, the focus is at 115, but parallax not as bad. One thing I did notice was I had to refocus the ocular piece on all 3 scopes to focus the reticle. The first 2 scopes were NF NXS 5.5x22x56, third was a Sightron 8 X 32.
Has anyone experienced this? Is there a fix? Is it the heat? Am I screwed?
Thanks, Mark W. [/quo
Couple of things
1. Loss of near vision is called presbyopia and occurs when the optic lens becomes stiff and its muscles can no longer bend it to optimize near and far vision. This is very common with age and doesn't mean your vision is failing. It can be corrected with: glasses optimized to allow focus on the front sight (iron); scoped sighting with setups that allow focusing the reticle AND adjusting for parallax. Red dots are another story as they are affected by presbyopia and astigmatism.
2. To focus on red dots you need correction for near vision, just as for the front post in irons, but optimized for a different pupil to sight distance
3. Astigmatism represents the effects of an irregular cornea which bends light in more than one angle (keeping it simple). This is more of a problem with red dots than scopes (as it often makes them quite "fuzzy") but affects both. To correct this you need more than a change in near vision magnification
How you solve this depends on your aims. For example, if your left eye works great wide open and you shoot with your right you only need to correct your scope or ironsight eye. You can get glasses that correct the shooting eye only, placing clear glass in the other side of the pair.
You need to see an opthalmologist (or appropriately credentialed optomotrist) and get an accurate eye exam. One who shoots or knows shooting would help (there are some and they sometimes advertise in shooting mags) but that's not necessary. In this day and age they know how to write prescriptions for a variety of non routine circumstances (such as for "computer glasses") and if you tell them what you need to sight on and the distances involved (front sight; red dot; reticle) they can create an appropriate Rx for your shooting eye.
I fix hearts for a living so take the above as a reasonable but not expert overview. On the other hand I've lived through this and have looked for and found solutions so you can too
Best of luck. Let me know if I can help.
