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Has anyone had success with compensating Rx's with a wrap calculator and satisfying the patient? If so, what methods were used to figure for wrap and tilt? Which calculator was used?

Thanks.

I hear a lot of talk about Rx calculator's for wrap frames, but not much about verifying PD. The common practice of verifying a PD is to take a ruler and measure the distance from the front of the...

I have one, but unfortunately have know intention of parting with it. Sorry.

I'm thinking that if I were to figure the power, in these formulas, using the radius of the front and back curves (combined with thickness and index of refraction), then when figuring for prism it...

The little things that a person should know, but really don't. That's why I love this website. Thanks for the reply.

What is it about applying Transitions to a CR-39 that changes the index of refraction, from 1.498 (or 1.499) to 1.501? I have never heard if this changes the refraction of the higher index lenses...

I spent some time yesterday going over my inconsistent results. It all boiled down to not having the formula plugged into my calculator correctly. I went thru the formulas piece by piece and got much...

I will be now. Thanks.

I must have blown it and you guys are scratching your heads thinking, "This guy is an idiot." In regards to my last post, does the formula I'm using take this into account and I'm not seeing it?...

Darryl,

I brought a couple worktickets home tonight, to work on you're latest post, and stummbled across something I never realized (or maybe still don't). The Rx is a CR-39 ST35 +2.00 -100 Ax 70...

J.R.,

Yes, the prism indexes are different. As is the ring depth and Prism ring diameter. I did run tests with a plano with 3 diopters base in and the prism amount required at the generator...

In the information that you and J.R. have provided, I am finally seeing that I already have the correct amount of prism needed for any given RX, using the formulas that you provided. Now, it is a...

I know that the software has a Prism Index setting listed for each material, but am not sure how or if it figures it into the equation. I will try and find this out. If the Prism Index is taken into...

I am seeking some more advice, as I seem to be stalled in my search. Even though I would like to be able to duplicate our workticket, I realize it helps to know how to walk before you try and run, so...

Things have been really hectic at work and at home, however, I still work on it every chance I get. I don't have it figured out yet and still plan on purchasing some more books to help me out. This...

I'm having trouble making sense out of the formula in this article.

Prism= 100(P1+P2- t/(n-1) P1+P2)x

I'm not looking for the answer, but I would appreciate some guidence. Here is where I'm...

I agree with what you are saying. I have your book and one by Clifford Brooks that I am working with to help me along. I plan on purchasing the ones everyone has suggested, also. Unfortunaltely, I'm...

I'm going to be out of town thru Wednesday, but will take a look on Thursday. The only reason I am doing all of this is to try and learn. I feel that if I can duplicate our workticket with an Excel...

I never really gave Darryl's formula's a chance with a bifocal lens. At the time, I was concerned with a single vision lens and determining the affect of an oblique axis.

Here is what I come up...

I wasn't able to duplicate the prism and prism axis that our system came up with, so I thought maybe that the Index of Refraction might play a part in figuring the amount of prism needed.

Here is...

Thank you to everyone for the response. Although I've been in the lab since I was a kid, this is the first time I am really focused on studying optics. J.R. gave me one of my first real eye openers...

Thanks for leading me to this article. I'm not having much luck yet, but will continue to work on it.

I realize that for SV this isn't extremely important, but would it be for Bi's and Tri's? When I try to duplicate our workticket with these formulas - SQRT(V^2+H^2)=Prism and Tan(V/H)=Axis - I don't...

Sorry to be so persistent, but I might not be asking the right questions. I think I need to be asking how to compensate for the prism angle, when trying to counter the OC moving vertically.

Here...

Then going back to my opening question, is there a workable formula that will calculate this induced prism caused by an oblique axis? I would think that it isn't very criticle when you are blocking...