Franklin Bifocals

[THE MEB]

I apologize upfront, this is a rookie question, but it needs to be addressed by me.
I was under the assumption that Franklin Bifocals were the same as Executive Bifocals, they jsut changed the name to execs several years ago. But after reading some of these threads it seems that my assumptions were incorrect. Please don't beat me up too badly on this one, but my curiosity is just getting the best of me on this one.
I know, you know what they say about assuming? I have heard that line too many times, so please have the common courtesy to not be too harsh.

[Chris Ryser]

I was under the assumption that Franklin Bifocals were the same as Executive Bifocals, they jsut changed the name to execs several years ago. [/color]

Executive lenses are a one piece bifocal, while the Franklin is actually 2 lenses on top od each other,

Benjamin Franklin was a hyperope who likely required eyeglasses originally in the 1730s. By the late 1750s he was usually described wearing them and they became an integral part of his face, at least for distance use. Many paintings and contemporary sketches and satirical cartoons show him represented wearing his eyeglasses. He admitted that he could not “distinguish a letter or even of large print without them”.

[Jacqui]

They are made from 2 lenses cut in half and glued together. Another name for them is prism seg, although this is not really correct. A typical Rx may read

+1.00 -.25 x 180 4^BO

Add: +2.25 2^BO

The manufacture of these is best left to experts who make and have made many of them. The way that I make them also requires some speciaized equipment that most, if not all other, opticians and labs don't have.

:cheers:

[RGC_man]

They tend to be thinner than execs whose substance can get pretty thick on the top portion, even if the outside of the reading seg is near knife edge. But as hinted at by Jacqui, they really come into their own if precise prism control is required, as you can position the centres exactly where you want. Some execs do inset the reading seg, but it can still be a bit of a lottery or compromise for centres.

[THE MEB]

let's see if I understand this correctly, because as you know it can be complicated when talking of prism, in that lenses are prisms, no matter what the rx, but my rx, like many, are a different animal.
I am at home, so I do currently have access to my rx, but it reads close to this:
OD -.25 -1.00 X90 PRISM 1UP,4IN
OS -.75 -1.25 X90 PRISM 1DN, 4IN
ADD +2.50
(ALSO, I refract at 30 DEGREES PRISM of some kind for near, but was told not to consider having it filled because I would get so nauseous trying to wear it that it would be impracticle.)
I was wondering if filling my full rx in a franklin bf would work. I have been unable to read with eyes at normal downward glaze for over 5 minutes without them watering out of control and feeling tired where I just want to lie down for 15 minutes. Because of that, I can't remember the last time I read a book, even though I must say reading is a lot easier on the computer since there is no downward gaze componet.

[Doug in Hutch]

Executive lenses are a one piece bifocal, while the Franklin is actually 2 lenses on top od each other,

This confusion is caused by the fact that most sources of lens info--both those aimed at consumers and at professionals-- do explicitly state that executive is another name for Franklin bifocals. This was true while I was in optical (1991-2005) and a quick Googling shows that it's still true:


http://www.allaboutvision.com/over40/segmented.htm (3rd paragraph)
http://www.sve.com/lenses.html (description of executive bifocals)
https://www.ecpmag.com/cetests/previ...aspx?testid=20 (look at question 16)

This seems to be a situation similar to the misuse of the word hacker, which is so ubiquitous that few people under 40 are aware of the real definition.

[THE MEB]

thank you Doug for making my inner child feel slightly better. It is comforting to know that I am not the only optican with way too many years in the business, that didn't understand that franklin lenses and execs were not the same animal.

[chip anderson]

Don't glue (gives too much reflection). Leave juncture frosted!
Special tools: Disc sander & file
Mount each pair of lenses in frame.
Mark with indellible marker 2 mm higher on near lenses, 2 mm lower on distance lenses with indellible marker .
Split along line with dremel disc.
Place on disc sander and remove all but 1/2 mm from each lens of desired side (take care to keep lens flat in all axis(s).
Take coarse file and carefully stroke lens on file with file laying on a flat surface.
Now take fine smooth file and hand file until both lenses fit perfectly in eyewire.
Clue: edge bevels should perfectly alighn when ready.

Note: If you don't have a small disc/belt sander you can get same for about $60.00 at home depot/Lowe's or similar store. You should be able to charge enough for first job to clear this.

Chip

[Jacqui]

Chip and I use different techniques, although the end result is the same. I do use glue as I have found a way to dull it and not cause problems (and keep my insurance company happy :) ). I have made custom jigs to hold the lenses in place during glueing so that they do stay straight and I use a flat 600 grit grinder to flatten the joint prior to glueing.

More thoughts: It's possible to do all kinds of weird things using this process. I've made trifocals, polarized, photochromic, high base for wrap frames, glass, etc. Someone a while back wanted an Overveiw lens, this would be possible using this process too.

Do a search for Clive Noble, the man was a genius at making them.

[Jacqui]

let's see if I understand this correctly, because as you know it can be complicated when talking of prism, in that lenses are prisms, no matter what the rx, but my rx, like many, are a different animal.
I am at home, so I do currently have access to my rx, but it reads close to this:
OD -.25 -1.00 X90 PRISM 1UP,4IN
OS -.75 -1.25 X90 PRISM 1DN, 4IN
ADD +2.50
(ALSO, I refract at 30 DEGREES PRISM of some kind for near, but was told not to consider having it filled because I would get so nauseous trying to wear it that it would be impracticle.)
I was wondering if filling my full rx in a franklin bf would work. I have been unable to read with eyes at normal downward glaze for over 5 minutes without them watering out of control and feeling tired where I just want to lie down for 15 minutes. Because of that, I can't remember the last time I read a book, even though I must say reading is a lot easier on the computer since there is no downward gaze componet.

Why don't you try a pair of reading glasses at the full Rx first.

[harry a saake]

MEB, there are many names sometimes in this business for the same thing, by different manufactures, executives at one time were also called duallens by Bausch and Lomb, what they all are is a continuation of the franklin.

[Robert Martellaro]

Why don't you try a pair of reading glasses at the full Rx first.

This may also be of interest-

http://www.bookholder.com/

[Happylady]

thank you Doug for making my inner child feel slightly better. It is comforting to know that I am not the only optican with way too many years in the business, that didn't understand that franklin lenses and execs were not the same animal.

I didn't know either, and honestly, I didn't know anyone still made orginal Franklin style bifocals anymore.

Do any of you make these yourself or are there labs that make them for you? How often do you use them?

[THE MEB]

thanks everyone for your feedback on the franklin, and what I might do to help me with my reading problems due to muscle imbalances. By the way, I have had this problem my whole life, it was a bear making it through college, but our office shares an adjoining reception area with 5 wonderful OMD'S as well. Subsequently, I have been tested to see if I would be a good candidate for muscle surgery as an adult, and unfortunately I am not. Even though, as an aside, I was plagued with migraines for 20 years, the last 2 years that I had them were a daily occurence. I went to several docs and finally ended up seeing a neurologist that specializes in headaches. After trying every med known to man he siad we should try botox, which I did. It took 3 sessions, about 40 shots a session, on the forehead down the temple into the neck and trapisias muscles, but finally, miraculously, the migraines went away. It was unfortunate that botox hasn't helped my fibromyalgia though. I bring all this botox history up, because that is typically what they use in muscle surgeries of the eye, according to the OMD.

[Jacqui]

I didn't know either, and honestly, I didn't know anyone still made orginal Franklin style bifocals anymore.

Do any of you make these yourself or are there labs that make them for you? How often do you use them?

We (the high school kid, Diane and I) make 3 - 4 pairs per day average. We've shipped to almost all the Western Hemishere, Europe, Saudi Peninsula, Hong Kong, Taiwan, Japan, Korea, Polynesia, and the lonliest place in the world Pitcarin Island. There isn't a large call for them, usually convergence problems, but when they're needed they are really needed.

P.S. I do charge what they are worth and have no problems getting it.