Eye Exam & New Glasses

Just in from my annual eye exam.  Prescription had not changed much.  Insurance pays for new lenses and frames I don't need.  Told the Dr. that I'd like a single focal lense for a length 6-8 inches from the end of my clenched fist.  Explained what it was for..  She ran the chart out to the length and flipped lenses to find the one I liked.  I'll pick them up tomorrow.  There will be no more of holding my head at an awkward angle to see through the middle lense of the trifocal lense.  BOOM! Marx Optical is your friend!

Did you ask for "polycarbonate"?   If not, consider changing to these, for safety.

How does one get the proper lenses if one is using a red dot? Standard distance prescription without the progressive/reading portion?

In my case, I found out that the red dot is supposed to "appear sharp" along with the target.  They gave me an eyeglass prescription for distance, meaning the target, and the red dot, both are clear and (acceptably) sharp.  I don't have astigmatism, so I didn't need a prescription for that.

I assume my acuity has everything to do with my eyes, not the glasses, that I have limited acuity at seeing things in the distance.  I was told Brian Zins can clearly see an X in the middle of a bull.  My eyes are not that good, and I don't think they've ever been that good.

On the other hand, since I'm following Dave Salyer's advice on "area aiming", my glasses, and the dot from a good red dot sight are both all that I need, at least as far as vision is concerned.  Acuity isn't the limiting factor.  All "the fundamentals" are far more important.

Red dot should use standard distance prescription.

Open sights are a bit harder to quantify. The theoretical best prescription would be distance prescription plus about +1.25 depending on your arm length, but most shooters find that too strong and prefer distance +0.5 to +0.75.

The cheapest way to get a good prescription for open sights is to get a few pairs of cheap drug store cheater glasses in +0.5, +0.75 and +1 and see what the sights look like at the range. You can also get stick on lenses intended to make your own bifocals to try.

One more point of info. Polycarbonate is pretty lousy optically but it is the only material rated for safety glasses. CR39 is slightly better optically but still shatterproof plastic. I don't know about any other materials options. CR39 won't stop a bullet, but should protect against minor impacts (cases ejected, splash back etc). They are your eyes and your decision.

mikemyers wrote:
I was told Brian Zins can clearly see an X in the middle of a bull.

To be more specific, as discussed in Shooting Sports USA last month, Brian Zins has a distance Rx of +0.75 D to see the target clearly while using the dot scope.  He then uses a plus add of +0.25 D or +0.50 D to help see the front sight of his iron sight pistols.

Norman

SteveT wrote:One more point of info. Polycarbonate is pretty lousy optically but it is the only material rated for safety glasses. CR39 is slightly better optically but still shatterproof plastic. I don't know about any other materials options. CR39 won't stop a bullet, but should protect against minor impacts (cases ejected, splash back etc). They are your eyes and your decision.

One factor which many may not factor in would be how thick the prescription lenses are.  Of course, the thicker the lens, the stronger the lens would be. 

Shooters may also consider the lens materials and its Abbe Values.  The higher the Abbe Value, the better the optical quality with less aberrations. 

59  Crown Glass
58  CR-39 Plastic
45  Trivex
30 Polycarbonate

You may be surprised that many pre-made shooting Rx lens materials are made of CR-39 plastic.  One may consider Trivex which is lightweight and offers superior impact resistance for safety.

Norman

Thanks, Norman.  Because of what you wrote, I wanted to find out more about "Trivex", which led me here:

https://www.smartbuyglasses.com/optical-center/eyeglasses/polycarbonate-or-trivex-lenses

I never heard of "Abbe value" until now.  Maybe the reason my polycarbonate lenses don't have the same "acuity" as my regular glasses, is due to the Abbe value.  Lots of new things to consider.   Like I said, thank you!