It won’t necessarily hurt you, but it could impact your business if you’re not aware how tracers can automate your practice.

With so much computerization built into optical machines these days, it’s easy to overlook the technology that makes them work. If you own a tracer or are considering the purchase of one, either built into a finishing system or a stand-alone unit, you can make them perform better if you understand what makes them tick.


Reproduction of three-dimensional shapes requires the use of complex algorithms that predict alignment of the next pixel in a continuous three-axis graph. The mathematical basis for these algorithms was first discovered in 1912. However, it wasn’t until 1962 when the French engineer Pierre Bézier used them to produce the shapes that formed auto bodies for Renault and later Citroen. With the advent of computerized 3-D graphing, these computations are the basis for modern computer-aided design and graphic design today. They are what tell your dentist’s 3-D printer how to shape your new crown, and they are what send your eyecare professional’s tracer and edger the shape to fabricate lenses. They are still referred to today as “Bézier Curves.”

Why is this important to an ECP? Knowing that engineers have already figured out the math lets you feel assured that the reproduction of unique shapes is possible. For example, the Weco E.6 edger combined with the Weco C.6 optical-camera-assistedGravitech tracing system’s Bézier Curve algorithms put the “Smart” in the company’s Smart Design 2.0 technology. Knowing this lets you use your wildest imagination in determining the lens shape of your next three-piece rimless mounting.


Not all methods of determining lens shapes are the same. With that said, do not discount a particular type of machine just because it uses a tried-and-true method such as “stylus” tracing. Today’s stylus tracers not only determine the basic two-dimensional shape that first-generation tracers could, but they also determine exact three-dimensional bevel placement for wrapped frames. They match bevel depth to bezel depth, making delicately small bevels for thin metal frames and up to mega Z87.1 industrial bevels for safety frames. They can determine the need for a shelf bevel and the placement of notches and grooves if necessary. They do all this with the gear-driven accuracy of a Swiss watch.

A great example is the Santinelli XtremeD LT-980 and LT-1200 Tracers. Among the characteristics that make them unique is the fact that these tracers use half of the stylus “pressure to frame” of previous generation tracers. This results in less distortion of eyewire shapes, even on the most flexible frames. The use of tungsten carbide on its uniquely shaped stylus tip provides a friction-free gliding action during a tracing cycle, which is another reason for its accuracy.


Many new “tracers” are often combined with other lab-processing features such as lensometry, layout and blocking. Since these functions are so relative to each other, it makes sense to combine them and reduce the amount of time it takes to physically handle a lens. The Coburn HAB-8000 Exxpert Automatic Lens Tracer/Blocker is one of these machines. Enter the frame and measurements, trace the frame, take a digital image of the shape, place an uncut blank on the prescription-verifying table, touch “start,” and let the “Exxpert” do the rest.

It is so accurate, it can identify where to place holes and slots for drilling, and it can automatically detect all lens types, such as single vision, progressives and bifocals. There is no need to “dot up” single vision lenses. Thousands of jobs can be saved on the SD card, either numerically or by customer name. You only touched the lens once, so the amount of time you’ll save is an important benefit when incorporating these machines into your practice. The HAB-8000 can be used with all of Coburn Exxpert and Excelon edgers or as a stand-alone unit in a lab environment with a lens-ordering connection available.


Stylus-free shape recognition is now possible with the use of digital camera imaging. The Mei Shape Finder 2.0 is just one example of this type of tracer. The Shape Finder 2.0 differentiates itself from other camera-based units with its unique use of multiple camera lenses and an internal lighting system. The purpose behind this technology is to eliminate the perspective effects of field distortion and provide a perfect edge profile. The Shape Finder 2.0 will eliminate the need for “test lenses” when shelf beveling, notching and drilling because it can create a precise OMA protocol file in just a few steps. When paired with a Mei edging system you will be able to mill those popular wrapped notch-and-hook, shelf-beveled shapes that are typically sent out to frame manufacturers for processing.

The Weco C.6 Auto Blocker also traces without a stylus. With wavefront power mapping lensometry integrated into this retail blocker, the unit allows you to superimpose the shape directly onto a contour power map of a progressive lens, verifying for the operator that the shape is going to work. The use of the Gravitech tracing system allows a digital “picture” to be taken of a lens shape as well as hole and notch placement by simply putting a sample shape on the tracing stage. The trace is completed in seconds. Because it uses neither clamps to hold the frame nor styluses that could apply too much pressure, among the advantages of this type of system is the undistorted reproduction of the lens. Even with the massive amount of data this machine gathers on just one job, it can store up to 10,000 shapes or 5,000 jobs.

New stylus-free shape recognition found on systems such as the Briot Perception can determine the exact bevel required to match a frame’s curve in the X, Y and Z axes. It does this by balancing a demo lens front-side down on the tracing stage. The machine then maps the lens curves in much the same way modern corneal mapping machines do using patented Gravitech technology. Exact matching of these surfaces makes it possible to edge lenses so the frame is not flattened or misshaped when the lenses are inserted. This is an important factor to ensure the finished eyewear will maintain a snug fit on the patient, especially since many plastic, nylon and composite frames have very little adjustment.


From Essilor Instruments USA comes an entire group of tracers known as the Tess Family. These include the Tess, the E-Tess and the L-Tess, with capabilities that expand from the first version to the last. All offer binocular tracing of all shapes, including the most intricate and high curved. An optional barcode reader is available on all three. While the base Tess model can store 200 integrated shapes in its memory, the E-Tess and the L-Tess can each memorize 1,000. In addition to the base model, the E-Tess also adds a one-to-one scale shape display to easily validate scanned images and a large set of shape modifications. In addition to that, the L-Tess features a raised tilted touch screen and increased motor robustness for higher production.

There is a lot more to your tracer than the on/off button. The more you know about the technology behind your unit, the better you’ll be able to use it.

AIT Industries, Inc. (Weco) 800.729.1959 • aitindustries.cominfo@aitindustries.com

Briot (Visionix) 800.292.7468 • briotusa.com

Coburn Technologies, Inc. 800.262.8761 • coburntechnologies.com

Essilor Instruments USA 855.EZ.FINISH • essilorinstrumentsusa.cominfo@essilorinstrumentsusa.com

MEI S.r.l. 847.357.0323 • meisystem.cominfo@meisystem.com

Santinelli International, Inc. 800.644.3343 • santinelli.comsales@santinelli.com

Michael Frandsen, ABOC, NCLE, is the owner of Quality Performance Ophthalmic, Inc., a custom service optical laboratory in South Jordan, UT.


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