What You Need to Know About Protecting Lens Markings

By Carol Savage
Preserving progressive lens markings during processing is critical to optimizing production and controlling costs. If markings are lost, they have to go back on—taking valuable time out of the production process. Whether you’re a small operation or a large lab, each extra minute per lens eats up valuable production time.

It is difficult to pinpoint the economic impact of lost lens markings. Since lens damage, poor frame fit or any other number of factors can contribute to the total number of non-adapts, it is difficult to track “lost costs.” Also, the rate of progressive non-adapts varies from lab—to—lab, However, since 85 percent of all multifocals dispensed are progressive, most industry officials agree that the problem of losing lens markings during processing can be costly and time-consuming.

LENS TECHNOLOGY CHALLENGES

Progressive lenses are supplied with two types of markings for layout, power verification, dispensing and identification purposes. Removable markings, which are inked on, identify the layout, verification and dispensing points of the frame. Permanent markings, which are engraved upon the surface, provide the identification and add power of the lens, as well as locator marks to reapply the ink markings when necessary. Markings include: prism reference point, distance reference point, fitting cross or point, near reference point, alignment reference marking, add power and logo or trademark. Dispensers mark “maps” of the lenses based on the position of the patient’s head and eyes, so the markings are highly individualized for each patient’s needs. The production lab relies on these sophisticated markings to be done precisely. Without these guide marks, the lab technician cannot produce a lens that the patient can adapt to.

Progressive Addition Lenses (PALs) address the need for variable vision correction by using aspheric lens design. Proper fitting and marking is especially crucial with PALs since the zones of clear vision are even narrower than conventional multifocal lenses.

SAFEGUARDING LENS TECHNOLOGY

To safeguard lens markings on any type of lens technology, some labs have begun using computer-generated software that duplicates basic markings. While not as painstaking as manually re-applying the markings, taking the extra time to remark the lenses, even with a computerized template, is nonetheless an additional step for technicians. Because these computerized systems are fairly expensive, they are more often found in larger labs. Small and medium-sized labs frequently use a less costly alternative to protect lens markings. They use a progressive lens protection film such as Cling-On from Venture Tape.

Cling-On is a clear, easy peel, self-adhering film designed to mask off all progressive lens factory markings. Cling-On is applied before blocking and after Rx and axis layout. It is placed over the progressive factory markings, and the technician can then block, surface, polish and deblock. Cling-On will peel away with the blocking tape leaving the factory markings intact. The lens is then ready for edging. Cling-On comes in two sizes: Cling-On (original version) is 62 mm; Cling-On Jr. is a smaller 46 mm winged version.

“I’ve been in the business for over 30 years, and I’ve used Cling-On Jrs. ever since they came out,” says Kim Owens, lab manager of Southern Eyes, a small wholesale operation in Concord, NC. “We use them so we don’t have to remark the progressives— it’s as simple as that,” says Owens.

The growing number of baby boomers reaching mid-life and beyond assures that the demand for bifocals and trifocals will continue to grow. The most successful lab professionals will make sure they have the best tools possible to be productive -- and profitable -- in meeting the growing demand for quality products in the future.

VENTURE TAPE MANUFACTURES OVER 1,000 STANDARD AND CUSTOM ADHESIVE PRODUCTS FOR A NUMBER OF INDUSTRIES, INCLUDING THE OPTICAL INDUSTRY. ALL OF VENTURE TAPE’S FACILITIES WORLDWIDE ARE ISO 9001:2000 CERTIFIED. FOR MORE INFORMATION ABOUT CLING-ONSÄ, CALL 800 343-1076, EXT. 2222 (U.S.) OR 0 800 962-957 (UK) OR VISIT THE WEB SITE AT WWW.VENTURETAPE.COM.

CURRENT ISSUE


May/June LabTalk 2017