Just another Flat-Top? The Free Form Digital Revolution

By Stephen Cohen
It’s another day at the dispensary and Mrs. Smith (your typical PAL wearer) is picking out her frames. With help from her friendly optician, she is guided through the high-end designers like Armani, Cartier and the like. She looks over the budget bar where the standard no names still hold sway with decent quality at budget prices. Not much has changed in this part of the eyeglass journey. The competition between frame vendors is fierce and brand names versus no names have their appropriate places. However something has changed quite dramatically when the optician selects Mrs. Smith’s progressive lenses.

There is no talk about this brand name lens or that brand name lens or that she saw an ad on TV or the POP display at the front of the store. There simply isn’t any discussion about lens brands at all. What is explained to her—if she already didn’t know—is that the lenses she will be getting are the best available for her Rx, her occupational needs and the frame she has selected. Whoa—something really has changed!

What has changed is that all labs are now making lenses using digital equipment and free form lens design software. No longer are labs forced to pick one of literally hundreds of front molded PALs. These dinosaurs have gone the way of the 8 track tape and the 3.5” floppy. All semi-finished inventory is now generic SV spherical front sided blanks. Instead of stocking four or five base curves, eight to ten adds and both right and left eyes (approximately 100 SKU’s per lens style), they now simply have to stock the base curves and that’s for one style and one material.

Just to drive this home – CR-39, Poly or Trivex, 1.56, 1.60, 1.67, equates to five materials for each style times 100 styles times 100 SKU’s per style (and there are more) so that’s 50,000 SKU’s (check my math but I think that’s right). Now with all PAL designs stored in the lab’s design software, the lab only needs to stock five base curves times five materials to equal 25 SKU’s to process any PAL. Let’s be generous and expand the base curve availability to 10 (this will also give us better optics and cosmetics) so we have replaced 50,000 SKUs with 50 and have a broader selection of base curves – “Ain’t technology grand!” Oops, let’s not forget about photochromics and polarized, which come in brown and grey—get out the abacus.

Digital surfacing equipment has dramatically improved the quality of each lens produced. This applies to conventional front molded PALs, Flat-Tops and SV as well as back-sided free form progressives. A conventional lab has somewhere in the neighborhood of 2,000 laps representing each and every power ground on the back side of a lens. These laps have a tolerance of a tenth of a diopter so one could easily error a typical Rx to .2 diopters. Digital equipment has no need for these laps or the labor required to pick them properly or the care to make sure they don’t have imperfections that will be transmitted to the Rx. Digital generators can cut curves to one, one-hundredth of a diopter. There are no more laps to pick. The inherent rejects and the labor costs are gone.

So how do we dispense the perfect PAL design? Well the optician and the doctor had to be taught some new tricks of the trade but luckily their local lab has taken the time to provide them with some tools and information to guide them. The doctor had to understand the sophistication of the lenses that could be made. Things like the width and length of the progressive corridor could be specified as well as the size of the reading area. The doctor could pass that on to the optician who then finished the task of frame selection and filling in the information for that Rx.

We now have a gizmo called the “Dispensometer” (this doesn’t get invented till 2010) that is similar to the conventional “Pupilometer.” It is simply placed in front of Mrs. Smith with her glasses on. This digital thingy measures her PD, both near and far, (you can now decenter PALs for right and left eye), her seg height, the pantoscopic tilt of her frame, her vertex distance and the wrap angle of her frame. With all these bits of information the lens design software can compensate her lenses accordingly.

For clarification, all these measurements can be taken today with various tools such as a distometer, a protractor and of course the mm ruler (the PD stick will somehow never leave the dispensing table). The only additional information the optician requires is if she is wearing an old style pair of PALs and what style that was. If this is her first pair of PALs, the optician will ask some basic information on how she will use her glasses. If the dispensary has a proper PMS/POS software system, then all this information including the doctor’s recommendations will be electronically recorded and put in a file to transfer to the lab.

If the ECP has the wisdom to have bought a frame tracing device, they will digitize the frame and it will be on its way to the lab in the same file. I’m sure that the fancy new “Dispensometer” will have a feature that could shoot the digital shape of the frame and include it in the order to the lab.

What has happened in 2014 is that backside free form PAL technology has come as far it can go. There are specific limits to what can be done with any Rx with any frame and all lens design software has the capability of taking this information to produce the best possible lenses for any patient.

Think back to the late 1960’s (assuming you were alive at the time – if not indulge me). The flat-top bifocal was all the rage. There was nothing better that could be done at the time. You had clear spherical distance, no distortion, no swim and clear reading. Of course you had to get used to the jump going from distance to reading and there was no intermediate (sorry trifocal wearers but it just wasn’t very good and there were virtually no computers). Millions of people did get used to the jump and there was simply nothing better. So after the American Optical, Shurons (yes I’m that old) and the Bausch & Lomb (B&L made lenses before contacts) of this world successfully touted their brand names through the 50’s and 60’s, it became clear that it didn’t matter who made the flat-top. It was the best you could do, the product was mature and the Americans and the Japanese made versions of the same product at commodity prices. The optician didn’t tout the brand nor did the lab. They promoted service, turnaround and price.

Guess what, in 2014 that’s where we will be again. Sophisticated free form software, the virtual flat-top, coupled with digital grinding equipment will produce the best lenses for every Rx. Brand names will no longer be a factor in lens selection. The regional lab for both wholesalers and retailers will be what the public requires. The art of edging will be most important since the surfacing of digital lenses will be done by equipment that will eliminate 80 percent of the labor cost. Cheap lens imports will not be considered. The Far East will not be able to make inroads simply because the digital equipment costs the same worldwide and the competitive labor advantage will be minimized. Their quality should not be as good and the freight, order placement and time involved will end their advantage. We will be dispensing the flat-top of the 21st Century.

Two last thoughts…

Will there be any independent labs left to make these new Flat-Tops?

The digital free form revolution is upon us; however there is one huge hurdle in our country to put these products in the hands of the American consumer and the labs to manufacture them. That hurdle is one very confusing patent issue that drags on and on and on.

One would think that if you owned a patent on this process you would want to license it to as many people as humanly possible, but that’s a topic for another time.


Labtalk June 2020