Polishing lens edges is easy, right? You just push a button and the job's done. Wrong. Even with today's automated technology, there are still challenges.

Equipment maintenance and failure, lens materials reacting differently, knowing when and when not to polish, being able to fix errors, and gaining and maintaining skills on a hand wheel prove there is still an art to the science of polished edges.

Keep samples of polished edges on hand. Photo courtesy of Nanofilm

POLISH PROTOCOL

With few exceptions, most labs polish polycarbonate, thicker-edged, and drilled rimless lenses.

As part of your lens presentation, it's important explain what polished lenses are and what they do. Also, always show patients what polished lenses look like. Keep polished lens edge samples on hand in different thicknesses and have a selection of polished lenses in frames made up for display on the frame board.

Polished demos in a rimless drill-mount, a full metal frame, and a plastic frame are recommended. Even better: show AR polished demo lenses, since AR and polished edges are a dynamic duo when it comes to enhancing lens appearance.

Still, even with good explanations and demos, there will always be those who don't want polished edges.

"We occasionally get returns on polished edges, usually because the patient didn't like them," says Scott MacLeod, lab manager with McLeod Optical Company, Inc., based in Warwick, R.I. "Some people experience reflections from the shiny edges. Others just don't like the way the edges look."

If a patient doesn't like the polished edges, it's usually cause for a complete remake, since altering a polished lens typically means it may not fit in the frame again.

"Although a lens polish can be dulled, if the patient is completely unhappy with the polish, I'd suggest a remake," says Magic Munson, finishing department manager at Katz & Klein Optical Laboratory, Inc., in Sacramento, Calif.

MATERIALS MANAGEMENT

Trivex, like poly, typically polishes with a high luster that most people find attractive. However, when polishing, poly and Trivex are more susceptible to
"railroad tracks," unattractive and unacceptable imperfections in the lens edge. Habitually checking for gummy swarf residue and cleaning the wheels help stop railroad tracks before they ever get started.

Sometimes it takes working with the equipment supplier to work through the problem, including modifying the edge polish cast if you process a lot of poly and/or Trivex.

"Our biggest problem with polishing is polycarbonate, although all of our edgers are capable of polishing poly," comments John Sutherlin, secretary-treasurer at Sutherlin Optical in Kansas City, Mo.

In addition, he adds, "we've been advised to alternate polishing different lens materials—not to edge two poly jobs back-to-back. But the
percentage of poly and Trivex has climbed to the point that it is impossible to alternate."

A simple solution to counteracting poly swarf is to take the time to clean the polishing wheels.

"Polycarbonate can leave a buildup on polishing wheels, so cleaning the wheels regularly is recommended," Munson says.

The best way to waylay polishing problems is to verify the material and to make sure the settings on the machine are correct for the verified material. Some labs and large practices also pre-test materials.

"We check the material removal rate by cutting a lens to a specific circumference measurement, polishing the lens by hand, and then rechecking the circumference
measurement and identifying the difference," explains Keith Cross, general manager of Northeast Lens Corporation in Newton Upper Falls, Mass., near Boston. "We want to know what to do if we have to hand polish the lens."

HAND POLISHING

Though edgers do most of today's work, it's still important to have the skills to use a hand-wheel.

"When polishing by hand, be sure to make continuous movements with the same amount of pressure being applied evenly," suggests Cross. "This will prevent marks on the polished edge, which are made by short stopping and starting movements."

Knowing how to hand polish lenses can help save a complete lens remake or offer stellar customer service when the patient didn't order polished edges but now wants them.

"Once a lens is edged it can't be put back on the edger for machine polishing, but can be hand polished," says Mike Fussell sales and customer service manager of Robertson Optical Laboratories, Loganville, Ga.

But the experts agree machine polishing does a better job and saves time. Sutherlin notes: "The time it takes to polish by hand versus on the edger gives operators incentive to be sure jobs come off the edgers with the best polished edge possible."