ask the labs
Safe Strategies
Karlen McLean, ABOC, NCLC
GLASS LIABILITY
Q I recently had a patient who is a farmer and insisted on glass lenses because he says plastic ones scratch too easily. I'm concerned about my liability. What suggestions do you have for situations like this?
A Outside of weight consideration—and whether eyewear with glass lenses will stay up on his nose where they belong—to give adequate protection, glass lenses are rated (as are plastic CR39 lenses) for basic impact under the 2003 ANSI standard. Poly and Trivex are rated for high impact and should always be used when the possibility of impact is great, such as flying debris from tilling a field or kicking cows.
Poly and Trivex both come with a factory-applied scratch coat. Explain the differences; the patient must decide what will work best for his or her environment. If you're still concerned about your liability, make notes of what you discussed and have the patient sign off on his or her decision.
—Jim Knapp, customer service, Airgas Protective Optics,
Germantown, Wisc.
SAFELY AR
Q Should safety lenses for use in an industrial setting be AR treated or not?
A We recommend AR polycarbonate lenses for many industrial environments in the United States. AR provides all of the same scratch-resistant protection, optical clarity, and ease of cleaning benefits for safety eyewear as it does for the dress eyewear segment.
Some industrial applications that can benefit from AR lenses include: inspection jobs, office or factory computer work, night driving, factories where intense overhead lighting causes reflections and glare, factories with low lighting, and for workers experiencing eyestrain or headaches because of reflective glare. As with any lens product produced for safety use, optical labs should follow the appropriate ANSI test requirements.
—Dana Dixon, marketing manager prescription eyewear, 3M Company Occupational Health and Environmental Safety Division,
St. Paul, Minn. (via iCoat Company)
| Wet or Dry? |
|---|
| Q I've heard that both wet-cut and dry-cut edging works with Trivex lenses. Which is best? A It's better to wet-cut Trivex with a carbide roughing cutter and finish wet with a diamond V or flat wheel. This method makes a much better-looking final product as it does not get hot and melt. This is really true on flat-edge lenses, such as drilled rimless or nylon groove mountings, because the edges are smoother and give a nicer luster to the lens' edge. This method produces a much better product all the way around. —Jon Jacobs, president, Superior Optical Lab, |
If you have a question you'd like to have answered in Ask the Labs, send it to Karlen McLean. Email: Karlen.McLean@WoltersKluwer.com. An archive of past Ask the Labs columns can be found on the Eyecare Business website at www.eyecarebusiness.com.
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