EYE ON EQUIPMENT

Achieving Polarized Perfection

6 edging strategies for this premium sun lens

Second-pair sales are a bona fide business builder, and Rx sunwear ranks at the top of the list when it comes to a second pair that every patient needs. In fact, according to the Eyecare Business Market Trends Study 2015, polarized sunwear leads the pack in sun lens options sold today—and 75% of ECPs have seen an increase in polarized sunwear sales over the past two years.

It’s no wonder—polarized lenses offer great features, such as glare control and enhanced clarity, and lens manufacturers are providing some excellent premium options in the category.

Taking advantage of your in-office finishing lab is a fast and easy way to provide your patients with sunwear. By handling the finishing yourself, you can offer top-grade Rx sunwear, quickly.

We asked some lab experts for their strategies for edging polarized lenses perfectly, the first time.

MOVE THE BEVEL

The polarizing element (usually a film) can pose an aesthetic issue with semi-rimless styles and frames with thin fronts because the edge can protrude beyond the frame and the film may show. This is especially true if the wearer is a very high minus—the thicker edge will likely protrude a bit from a thin-fronted frame. However, the advanced features on modern edgers allow for the operator to adjust the placement of the bevel, notes Mark DiMeo, owner of Mark Optical in Plainview, NY.

A slight adjustment will place the bevel in front of the film, so if it shows at all, it will be behind the frame. Of course, if that isn’t possible (or desired), choosing a different frame style with a thicker front is the answer.

PAINT THE EDGE

Depending on the curve of the lens and the strength of the Rx, the polarized film edge may not be hidden simply by moving a bevel. In those cases, painting the edge the same color as the tint will take care of the aesthetics. Tinting the entire lens prior to frame insertion will also hide any film rings, DiMeo says.

SMOOTH EDGES

Sharp bevels are a desired result when edging. In particular, sharp bevels are helpful in keeping the lens secure in wrap frames. However, those sharp bevels can flake just a bit when being forced into the frame, especially on the nasal edge. That can cause the polarizing film to “catch” a little bit on the frame edge, DiMeo notes. To avoid that, he suggests: “With a light hand, dull the bevel edge just slightly, around the nasal edge and corners, with a handstone.”

WATCH THE CURVE

Wrap frames are popular choices for sunwear, for sure. But try to steer high-minus patients away from high-wrap sunglass frames, with which it will be harder to hide the ring of the polarizing film.

“If you can’t, check with your lab and get a base curve [lens] that is closer to the frame curvature than you normally would use with a high minus prescription. You’ll also probably need a design that offers Rx compensation for the curves,” says Bob Westlake, branch manager of Walman Optical in Traverse City, MI.

KEEP IT COOL

Years ago, the polarizing film could get burned and delaminate during edging. Today’s superior materials have all but eliminated that problem, says DiMeo. However, he still suggests making sure the lens stays cool during edging. Wet edging systems usually take care of that, but you should also keep your edging wheels sharp to avoid unnecessary friction.

FIRST-FIT CUTS

A lens that’s a millimeter or two too large for the frame, especially in wrap frames, may result in a tiny bit of delamination at the apex of the bevel, the wafer, and the lens edge. “Edging to proper size is vital,” says Westlake. “Make sure your machine is calibrated correctly and that your blocking pad is tight for full coverage. You don’t want any stress in any part of the lens.”

Though they provided these tips to help ECPs eliminate expensive redos on polarized edging jobs, both lab experts stressed that contemporary polarized lenses do not present the finishing challenges their predecessors did. Gone are the days when delamination and other edging issues were common, they say.

“The lenses and the polarization processes have come a long way,” DiMeo says. “If retailers stick with the quality lenses, they shouldn’t really have much of a problem.”

—Susan Tarrant