L&T: RxPertise

Mar
2011

Getting an Edge-ucation

How ‘smart’ edgers ensure a perfect fit


Photograph by Iris Johnson

By Barry Santini

“There’s nothing like beveling a nice, thick lens!” Wise words, uttered back in 1974, by one of my master teachers, both a mentor and craftsman, Professor John Williams. The state of the art for edging lenses in those days consisted of a layout protractor, a china marker, a lens cribber, a large ceramic handstone and one of those new “whirligig” diamond-wheeled “automatic beveling” edgers. All the proper ingredients needed to process the main lens recipe of the day: glass. But even with such equipment, considered advanced for its day, a tremendous amount of hand skill was both necessary and expected from anyone who professed to have mastered “bench skills.” Today’s computer-numeric controlled (CNC) edgers, with millions of lines of code contained within complex software algorithms, can easily provide almost the entire skill set of the accomplished benchmen of yore.

Today, these machines can also perform functions that would have amazed my optician father on a level with his witnessing of men landing on the moon. From millimetric lens sizing to frame-matched bevel placement, “smart” edgers can do it all, including precision lens chamfering, drilling, faceting, grooving, polishing and even routing. Yet, the most sophisticated models can also do one thing my father would have never considered in his wildest dreams—replace the benchmen he would have considered essential for any busy optical office. Today, in an era when controlling costs is paramount for remaining competitive, the question to ask oneself is not, “How can I afford a smart edger?” but rather, “How can I afford not to?”

TO EDGE OR NOT TO EDGE?

The debate about the cost and perceived hassle of in-office edging has gone on for decades, so what’s different in the current dialogue now? In a word, it’s called the internet. With easy access from any computer, smart phone or tablet, the public is fast becoming accustomed to accessing a universe of goods and services—including optical—at their fingertips, 24/7. With the rapid commoditization all this entails, relying on just products or brand offerings as your office’s main differentiator is no longer sufficient.

An ECP’s office must convey and prove their value-added to their client base, whether old or new, literally everyday. Under the onslaught of online, a brick and mortar eyecare office may easily for get the trump card it holds in the high stakes game of internet eyewear: convenience. When a local parent needs their child’s eyewear fixed, fulfilled, adjusted or replaced immediately, the perfect opportunity exists for a service-oriented ECP, armed with the latest tools and technology, to put them back on the road fast. Whether you have an in-house smart edger could very well be the key to your business’ salvation. A smart edger not only makes delivering high-quality eyewear a snap, it lets you tackle the remount of a client’s own lenses with confidence and speed, even with progressive lenses. More than ever, consumer expectation about eyewear convenience is benchmarked against their automobile ownership experience. Not only shouldn’t the car break down, but if it does, repairs should be fast, efficient and done at reasonable cost. In eyewear speak, lenses should never fall out, nor should their frame’s eyewire snap. For either case, a smart edger will help you deliver both the best fitting lenses ever and tackle the remount of a client’s own lenses with confidence and speed.

MAKING LENSES FIT: THE PROBLEM
During the 1950s, when plastic frames (or zyl) and glass lenses dominated eyewear fashion and vision correction, keeping lenses in place was relatively easy. Eyewires were constructed with deep grooves, and lenses made of glass were not susceptible to warpage. Stories of lenses that would spontaneously fall out of frames were unheard of. Frame sizes and shapes were also small and symmetrical, making lens fit and retention very straightforward.

Beginning in the late 1970s, with frame fashion going big and bold along with more market penetration by hard resin plastic, making lenses fit and stay within these frames became a challenge for any edger, in-office or not. Plastic lenses would often deform, warp or shrink, and “PLOP!”… Out would fall a lens at the most inopportune time. The trendy, trapezoidal shapes that hallmarked the fashion of 1980s Laura Biagiotti sunglasses, along with the oversized must-have sunglass of that decade, the Porsche Design Carrera aviator, presented significant problems to both the edging equipment as well as the hand skills of most opticians of that time.

As precision frame tracers and patternless edging replaced patterns and handstones, a new era of even more sophistication in lens fitting dawned. There’s no longer any question or debate about it: Patternless lens finishing is infinitely more precise in preparing lenses for any frame, whether it may be plastic, metal, grooved or rimless. But even as edger technology progressed, other challenges surfaced. With a recipe made of frame shapes with very narrow B dimensions and rectangular corners, along with lenses that featured super-slippery anti-reflective coatings, both lens fit and fabrication were plagued with new issues.

The first problem was that patternless systems, although very precise, had difficulty accurately rendering these large-difference shapes. The finished “A” dimension was often larger than desired. Combined with a frame possessing a straight upper-eyewire profile, prescription lenses would either warp or bow, and the mismatched lens shape caused the frame’s eyewire to twist and roll. In a perfect storm scenario, both would occur in a single pair of eyewear. This not only affected lens retention, it negatively impacted overall frame adjustment. The result was very unhappy clients, with their lenses falling out as their frames fell off their heads.

The second challenge came courtesy of new, super hydrophobic anti-reflective coatings. Engineered to shed both water and dirt, as well as easy to clean, these super slippery lens surfaces created havoc for patternless edgers designed to process non-coated lenses fast and efficiently. Spoilage from lens slippage in the edger delayed thousands of jobs, escalated costs and made both ECPs and their labs appear less than competent. Luckily for us, the elves in the edger-engineering department never sleep.

The Importance of Craftsmanship In Eyewear
During the 100 years between 1860 and 1960, there was often little distinction made between a “dispensing” optician, who primarily measured fit and dispensed eyewear, and a “benchman” who primarily worked in the lab only making the finished product. An optician was expected to do it all. In the days before licensure or schooling existed, the traditional path for acquiring the optical skills necessary was through a guild. Beginning as an apprentice, one might start by sweeping floors, as my father did in his early days. Exposed to the art of making eyewear, an apprentice could eventually progress through to the journeyman phase, and ultimately, with the approval of other masters, become a master himself. Along the way, the primary emphasis was on craft and skills, and less on a mechanical understanding of the real technical issues involved. This resulted in the skill to craft all types of eyewear albeit, guided by various “rules of thumb.” Optical handicraft comprises an interesting skill set. On one hand, the very nature of working by hand means precise repeatability can remain elusive. Yet, these same skilled hands could finely tweak and fit lenses to an individual frame to a very high standard, as long as the proper amount of time was available. The standards that guild opticians achieved in marrying optics and frames together lay near the pinnacle of the finest hand craftsmanship.

As automatic edger technology began to infiltrate lens finishing during the 1950s and 1960s, the stage was set for less reliance on hand skills. Using patterns that replicated lens shapes, these machines could both quickly rough cut and bevel a glass lens—operations that were formerly separated. Over the years as edgers evolved, they delivered ever faster and more efficient lens processing power. And the need for skilled benchmen diminished. With the arrival of patternless edgers in the 1990s, the skill set of these machines exceeded that of most opticians, and they became the new gold standard in lens finishing.
—Barry Santini
MAKING LENSES FIT: THE SOLUTIONS
In order to improve lens fit and reduce process spoilage, today’s smart edging systems employ new technologies directly designed to address these issues.

IMPROVING LENS FIT AND RETENTION
To improve the fit of narrow “B” shaped lenses, as well as provide the option to customize rimless and semi-rimless lenses, three advanced technologies are included in all smart edgers.

3D Tracers—Instead of rendering a lens shape in two dimensions, like the projection we block with, 3D tracers measure the base curve of the eyewire. With this new parameter, the curve of the lens bevel can be set to any dioptric value desired.

Frame Fit Beveling Mode—Surpassing the old 1/3 to 2/3 Guild rule-of-thumb for bevel position, the frame-fit bevel mode automatically matches the curve of the lens apex to the frame being used. Benefits include significantly-improved lens fit, reducing lens warpage and frame distortion, as well as unwanted temple splay.

Shape Modification
—From time to time, experience points us to try to improve lens fit by changing lens shape difference. With a precision of 0.05mm, one can tailor a lens shape for improved fit and appearance. In addition, lengthening or shortening a grooved lens’ “B” dimension becomes child play. Whether you are making more room for a progressive, or trying to clear chubby cheeks, these shape modification modes, once used, are not to be without.

REDUCING SPOILAGE
New super slippery AR coatings have created headaches with increased spoilage from lens surface crazing and slippage during edging. Three new technologies have been developed to address these problems, and improve your bottom line:

Advanced Torque Feedback Control—The edger’s lens holder shaft is connected to a feedback circuit that measures the torque required during roughing and finishing cycles. Shaft rotation speed is monitored and adjusted to keep the lens from experiencing too much push-back during the grinding process.

Lens Circumference Determination
—At the beginning of the edging cycle, a moveable arm engages to trace the circumference of the uncut lens. Using this raw lens profile, the amount of material to be removed is calculated, and both lens rotation speed and feed rate are optimized. This method also utilizes both the known lens shape and finished size to refine torque control.

Roughing with Routers—Wheeled edgers have been praised for their exquisite lens finish and polishing capabilities. Dry edgers, employing router bits, excel at fast material removal with reduced slippage. Some edgers combine both to marry their best qualities. During the first stage of roughing, a router bit is deployed to cut off quadrants of excess lens material. Next, the lens profile is smoothed over and more material is taken away using advanced wheel abrasive profiles. You get the best of both in one edger.

WRAP FRAMES: THE NEW FRONTIER

In my father’s wildest dreams, he would never have conceived that prescription lenses would routinely be mounted in frames with an 8 or 9 base eyewire coquille. In his time, the closest he came was trying to wrestle some 7D base lenses into a 9D base Ray-Ban Balorama. He had about as much success keeping them from warping and falling out as I have had, until recently. The latest and most advanced edging and tracing systems today easily handle mounting lenses in 7D to 9D base wrap frames through the use of custom bevel profiles, also known as the “step” bevel. Sunglass styles featuring interchangeable lenses can now be done in your own office. Step bevel can also be used creatively in rimless work, trimming lens thickness and allowing custom lens-edge sculpting. Attention all optician-artisans: Your new “toy” has arrived!

USING MEMORY TO BRIDGE DISTANCE
A really neat, hidden feature of these smart edgers is the ability to memorize all the parameters of a finished job. From a custom rimless shape with modified drill points, to a wrap job done on a client’s own frame, it’s nice to tell your clients that you have saved all the frame information into memory, indexed to their name, for easy retrieval anytime they desire new lenses. For example, as some of my customers moved away, I’ve continued to supply them with new replacement lenses, accurately prepared for their favorite frames, all at the touch of a button. Many of my customers love this convenience, whether they live around the corner, or around the world.

CAN YOU AFFORD A SMART EDGER?
In the 1980s, a state-of-the-art edger cost between $5,000 and $6,000. Today’s super sophisticated smart edgers, taken with all the bells and whistles, can cost between $60,000 and $70,000. One might ask, “How can you justify that cost?” Easy. They can do more, so you can too. More jobs, different jobs, quick jobs—even while-you-wait lens remounts into a new frame—which can transform a one time walk-in into a customer for life. In my own shop, I am fortunate to have software installed that facilitates making magnetic sun clips for virtually any frame my clients desire. By having both 3D and low-plus AR computer/music lenses to offer, I can expand and enhance both the utility of any pair of eyewear and my bottom line. If you do the math, you’d be surprised to know that the profit realized from selling just three custom clips a week could cover your entire smart edger lease payment every month. That way, you can have your cake and eat it too.

THE PRIDE THAT COMES WITH CRAFTSMANSHIP
With the rapid changes overtaking our industry, from supplier consolidation, to health insurance, to the very idea that prescription eyewear is obtainable over the internet, it is more important than ever for brick and mortar eyecare practices to expand and leverage their service offerings into a value message focusing on quality, convenience and care. The enhanced repertoire of abilities and unrivalled precision that these smart machines can bring to your office cannot be overstated.

When I began, my Dad would often smile and tell me, “It takes at least 10 years to master all facets of finishing lenses.” And back then, he was right. I’ll never forget the genuine satisfaction I gleaned from hand beveling “a nice, thick lens.” Today, smart edgers can not only make you look very smart, they can restore the sense of pride and craftsmanship that makes a career in ophthalmic dispensing unique amongst the medical disciplines. ■

 

|