Need help figuring out correct add for my Irons glasses

First topic message reminder :

Gentlemen,
My eyesight has deteriorated rapidly in the last year and I have found it very, very difficult to shoot iron sights. I am slightly nearsighted, and have a prescription that works beautifully for dot shooting, but is worthless for irons. I can not pick up the front sight, and my eyes dart between rear sight and target - after a 900 of irons my eyes are so exhausted they are physically sore.

I know i should just go to a doctor and get a prescription with my gun, but I really don't want to deal with that hassle and I feel like I am pretty close to dialing in my iron sights needs, just need some advice from someone who understands better how prescriptions and readers work. The low power readers I need are not available in any stores around me, so I have to order one, wait a week or 2, try it, and then order another one. They are only $10, but it's getting tedious. My last indoor 900 I had such a hard time seeing the front sight I shot a marksman score.

My prescription for right eye is:
sphere -0.50, cyl -0.50, axis 100.
This brings everything into sharp focus and for irons is not good, i can see the target so well its really hard not to look at it, especially holes. I prefer the target to be a bit blurry. The holes are so huge on 50ft targets its impossible not to look at them.

The add that has gotten me the closest to what I want is +0.5 readers. That puts the rear sight in sharp focus and the target is blurry, BUT I still have a tough time keeping the front sight in focus. I have a scratch on it to look at.

SO,
1) Should I bump down to a + .25 add and try that? I am thinking it will be a bit too strong. If I only need my focal point moved out 6 more inches, would that mean I should bump down from +.5 to a +.4 diopter?

2) If i am ordering a custom grind on the internet, should I add my astigmatism values (cyl +axis) to magnification I want? Does it really matter if all i am trying to see is the front sight post and nothing else?

Thanks for the help in advance, and just to repeat this is all to save me from 1) going to the eye doctor like I probably should, and 2) buying the not-quite right prescription again online and having to do this again in a couple weeks.

From what I'm reading from many shooters, guns will not be allowed in their offices, period. Something else less intimidating would be needed.