Tech Talk Jan/Feb 2015

By staff


When producing quality digital lenses, one of the most important elements is the diamond tool used for generating the lens surface. To get the most from your diamond tooling while at the same time maintaining a consistent, high quality finished product is a matter of following some simple “Best Practice” recommendations.

First, and perhaps most importantly, always follow the manufacturer’s recommended maximum number of surfaces produced between sharpening. While there may be a temptation to save a few pennies per lens by extending the re-sharpening interval, the cost of even a half percent increase in spoilage far outweighs any possible savings that might have been gained. In addition, over-stressing the diamond can actually limit the number of times it can be sharpened. Every tool has a “wear zone” meaning the entire surface is not actually used during production. The greater the wear in this zone, the more material has to be removed during sharpening.

Despite being one of the hardest materials known to exist, in this configuration a diamond is very brittle. A chipped diamond has a substantially reduced life at best, and is rendered worthless at worst. Always keep diamond tools in their original packaging when not in the machine, and of course always use this packaging for shipping.

Last, but not least, when mounting the tool in its holder, always follow the manufacturer’s instructions including torque specifications for the holding screw. Over-tightening can damage or warp the tool body as well as make it difficult to remove when the time comes, further increasing the risk of damage. Ian Gregg, director of surfacing products, Satisloh



“Digital” goes hand-in-hand with “precision.”  Though more and more labs are embracing the latest digitally-based lens processing technology, many adhere to poor and long-held “manual” habits that are not only unnecessary, but costly. Even in today’s digital-based world of surfacing and finishing, old and costly habits are hard to break for many lab operators.

The fear factor of “what if it cuts small?” is a hard one to overcome when dealing with today’s costly lenses and/or specialty jobs, but it is addressable. Labs that adopt the highest level of lens processing automation can maximize their bottom line and overcome lens breakage fears. That solution requires a regimented and well-trained (by vendor) maintenance staff so operators of tracing and blocking technologies (if not automated) are as copious as the calibrated equipment they are responsible for. The risk or cost/benefit ratio is compromised when allowing the “fear factor” (e.g. in manual specialty edging cells) to lead versus investing in well-calibrated and maintained digitally-based products.

A tracer that provides the highest radii data whether through digitally-based stylus engineering or camera imaging is the genesis of a highest 90 percentile first-time fit result. A robust blocker or automated blocking technology is the natural extension of the tracing result and provides the next step in the digital transmission stepped process to the edging platform.  The edger, whether automated or manual, completes the artistry of the data it receives to the final first-time fit product. To cut something big is to diminish the entire process and devalue the technology and ROI. Steve Swalgen, national director – lab business - Santinelli International


Maybe you’ve heard that before but not in reference to digital surfacing.  You can be sure to expect the same bad outcome.  In digital surfacing, cheating is the over-taxing of consumables or other process parameters beyond the recommended values in order to save a buck.  But there is a huge cost to stretching those recommendations.

One great example is diamond life.  Let’s say the recommended diamond life is 2500 cuts and can be re-tooled 4 times.  The result is 10,500 cuts over the life of the diamond.  You’ve decided to extend the diamond life a mere 30 percent to 15,000 cuts over its lifetime.  Sounds reasonable right? The diamond still seems to cut well. After you exceed the recommended and tested diamond life, you will experience increased waviness, aberrations, center defects etc.  You should expect a yield of approximately 98 percent or better on a generator. This is why diamonds have a tested and recommended lifetime before re-sharpening.   An overworked diamond will cause a minimum yield decrease of 2 percent (about double the lens breakage), and most labs will tell you it is worse.  In the end, you saved $52 on consumables by stretching the diamond life by 30 percent, but at what cost? 

With the 2 percent decrease in yield, the consumables savings of $52 per diamond will cost you about $900 in spoilage (based on $10/lens for material and production cost).  In this example, over-extending diamond life resulted in a net loss of $848!  That does not include lost service time, questionable quality and other factors; only the raw costs of lowering yield by 2 percent due to “cheating” on diamond life.  With well tested and proven digital surfacing processes, cutting corners simply doesn’t pay. Kurt Atchison, president, Schneider Optical Machinery



Blocking:  Designed for digital and traditional lens processing, the E2G eliminates the need for alloy by using a reusable, machinable, and environmentally safe blocking material. The E2G also allows for full diameter lens support, which is critical for digital surfacing providing superior lens quality with a lower total cost of ownership.  It also features one-touch blocking, automatic block and lens detection, along with many other user-friendly features.

Surfacing: The new Cobalt Generator series and Cobalt polisher are the latest innovations from Coburn Technologies. Together they make the True-Form system; an innovative matched set of technologies for producing high-speed traditional Rx and free-form lenses. Working together these machines produce spectacular free-form lenses, but they are also designed to work separately with other manufacturer’s compatible free-form generators and free-form polishers.  The concept for the new technologies of True-Form came from feedback collected from dozens of lens processing laboratories around the world to build in an ideal feature set that our customers desire. 

Digital Solutions: HyperFLEX Digital Polishing Tools provide the lowest cost per lens with industry leading performance and life. The innovative design utilizes the latest in material technology and the SecureFit base reduces breakage caused by tool failure, tearing, and drop off. The Dual-Stage design, developed for Cobalt Polishers has been successfully adapted to create superior digital tools for CCP, i/aFLEX, and Toro/DuoFLEX machines. Matthew Brown, senior sales support engineer, Coburn Technologies


2014 saw the introduction of Camber, a revolutionary new digital lens technology developed by Younger Optics in partnership with IOT. Camber lenses are now being offered by a growing number of independent laboratories, most of whom market Camber lenses under a house brand of digital lens designs.

Independent laboratory Laramy-K Optical offers its brand, Integrity Freeform lenses, with Camber technology. Owner Janet Benjamin says, “We offer Camber lenses because they are simply the best technology in the market today. For Laramy-K, benefiting the wearer is the biggest benefit to us as a company.”

How does a Camber lens differ from a standard back-side digital progressive lens? It starts with an innovative new lens blank design, one that features a continuously increasing base curve from the top to the bottom of the lens. This helps to provide the appropriate base curve in each zone of the lens. Its sophisticated back surface digital design is enhanced with IOT’s Digital Ray-Path technology. Once processed, both surfaces work in tandem to create the Camber finished lens design, which offers expanded reading zones, improved peripheral vision, and a more cosmetically appealing (flatter) finished lens shape.

A wearer in Israel writes, “I am amazed with this design. It feels just like single vision. There is absolutely no distortion at the edges. I think this is the best progressive I’ve had in 30 years.”

Camber lenses are available in five materials, in 8 base curves. NuPolar and Transitions Signature styles are also available.  David Rips, president, Younger Optics


Labtalk June 2020