L&T: In the Lens Lab


A Day in the Life

 A Day in the Life

Or, “It Hurts When
You Do That!”—
typical day at COLTS Laboratories

By John Young

Over the years, I have received many requests for guided tours of COLTS so “In the Lens Lab” readers can get a glimpse of some of the things we do when testing lenses, frames, cloths, cleaners and equipment. It’s a little difficult to offer a “visual” tour here in the magazine—given the number of photos necessary—so I thought we’d try a written “tour” as seen from the perspective of a visiting customer.

Once upon a time—well, let’s just say it was this past summer—Sarah Johnson, a chemical engineer from Acme Lens manufacturing, decided she wanted to see for herself what happens to her company’s lenses during testing at COLTS. The names have obviously been changed to protect the innocent—and to make our lawyers happy. Anyway, Sarah came in with the lenses and began to watch the process that would eventually give her all of the information she needs regarding the performance of her new hard-coated lens formula.

Right from the start she knew it was going to be a great trip because we sent her out for a day on the beautiful Gulf Coast at famous Clearwater Beach. We weren’t trying to hide anything. When lenses first come into COLTS, they have to sit open to our laboratory-controlled environment for 24 hours before testing can begin. We do this so the lenses can acclimate to an ambient environment of 73 degrees and relative humidity of 50 percent. The next morning, we began the testing under Sarah’s watchful eye.

The first test was the Bayer Abrasion Test, where an abrasive material is washed back and forth across the top of the lenses for a specific period of time. We measured the coating “haze” prior to the test and again following the test. These measurements were then compared to an uncoated conventional plastic lens to see how scratch resistant the coated lens was compared to the uncoated standard lens. Sarah’s lenses scored a 4.55 in the test, proving they averaged 4.55 times more abrasion resistant than an uncoated lens.

Next, Sarah watched as we put her lenses through the Cycle Humidity Oven Crosshatch Adhesion Test, or “CHOCA” as it more affectionately known around the lab. This test correlates to actual wear and has proven to be an excellent method of determining how well a coated lens will wear in normal use. The life of A-R coated lenses can also be predicted by the use of this test.

This test is conducted in eight-hour installments over three days and it strives to duplicate real-world heat and humidity conditions. Again, we sent Sarah to the beach. At the end of each day, before we closed for the night, we passed along the results of the testing from that day to her when she came back. By the last day of the test, Sarah was pleased to see that none of the coating on her lenses had delaminated or crazed. Unfortunately, while she waited for her testing to be completed, she got a little too much sun while lying on the beach. (When visiting COLTS, having plenty of sunscreen is a great idea.)

Once these tests were completed, the data was entered into the COLTS information system and we generated a report for Sarah to take back to her company. With this report, Sarah and her company also had comparative information in the form of a frequency distribution curve. While names were not used (all test results at COLTS are kept confidential), the report did give her a good idea of how Acme lenses stack up against all of the other lenses in the industry.

All kidding aside, Sarah’s story shows the results of the work we do here at COLTS are far more interesting than the processes we use to obtain them. Sarah learned that our work shows how certain products compare to others in terms of performance and, in general, assists in ensuring that all of the industry vision correction products uphold certain standards of performance.
These tests, and the resulting data, deliver the message to the retailer that the lens industry’s overall quality is improving with innovative products. And that is a message 20/20 readers can take to the bank.

John Young is an ophthalmic lens expert with more than 25 years experience in the optical industry. He has worked for several lens manufacturers, including American Optical and Essilor, and is the former technical director of the Optical Industry Association. His company, COLTS Laboratories, is a Clearwater, Fla.-based independent lens testing facility designed to provide thorough and accurate quality and performance evaluations of spectacle lens products. His clients include lens manufacturers, wholesale labs, independent research organizations, large retailers and independent dispensers. The lab was the first U.S. ophthalmic testing laboratory accredited by the American Association for Laboratory Accreditation. It is also a Safety Equipment Institute-accredited eye protection/safety test lab. Young can be reached by phone at (727) 725-2323 and by email at