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COLTS LENS TESTING REQUIREMENTS 20 march 2015 opticallabproducts.com What You Need to Know When Testing Lenses BY KIMBERLY HUTTON AND DARYL NEELY COLTS Laboratories addresses some of the confusion surrounding ANSI Z87.1-2010 prescription lens impact testing. A BIG TOPIC of conversation and a source of a lot of confusion for lab managers has been the requirements for ANSI Z87.1-2010 prescription lens impact testing. The following is our attempt to break the information down into pieces and explain each part to make it more manageable, and the testing process easier. LENS MATERIAL Let's start with the Lens Material Qualifcation. You must test three lens samples for each substrate and coating combination offered by your lab. While this may seem daunting, it is really quite manage- able. Basically what this means is you must test your polycarbonate, CR-39 ® , and any other lens materials, for each combination of hardcoat (HC) and AR. We suggest that for Rx safety lenses labs limit the combinations of products they offer for safety prescriptions to keep their costs and liability to a minimum. The test samples need to be in a "V" bevel (uniform 115° +/- 5°) included angle bevel to a diameter 55.0mm +0.04mm/-0.25mm (2.17 + 0.002/- 0.01 in.) cut to 55mm round, plano power, and no steeper than a 6.25D base curve. An important factor to remember is the standard requires a "lens thickness" of at least 2.0mm. This means the entire lens, not just center thick- ness. This process must be repeated if there are any signifcant changes in product or process. While a change in product is self-explanato- ry, "signifcant changes" to processes are much less clear. While determining a "signifcant change" to the process is left to lab manage- ment to defne, some things to consider may be any new machinery (for example a new edger or coater) that affects your product. This test consists of a ¼-in. steel ball travel- ing at 150 frames per second (fps) (+/- 3 fps) impacting the surface of the lens. LENS FAILURE What is considered a failure on the Lens Material Qualifcation? • Posterior displacement of the lens completely through the test/lens holder • Fracture of the lens • Any detachment of a portion of the lens from its inner surface or • Any full thickness penetration of a lens Failure of any one of the three lenses on this test constitutes a failure of the lens material/coating combination being tested. LENS MOUNTING Once you have passed the Lens Material Qualifcation portion of the test, the next step is the Lens Mounting Qualifcation of the complete eyewear. This portion of the test is designed to verify your lab's ability to correctly edge and mount lenses into various types of frames. Lens Mounting Qualifca- tion is composed of two separate tests: High Velocity Impact and High Mass Impact. For the High Velocity test you need to test six pairs of glasses for each frame variant. That seems like a ton of testing but that means you must test each frame "type." The frame types listed in the standard include metal, The Lens Mounting Qualifcation Test is designed to verify a lab's ability to correctly edge and mount lenses into various types of frames. This lens holder is used when conducting the Lens Material Qualifcation test.