Eye Opener

Tom Engardio
Director of research and
new product development
Signet Armorlite

By Andrew Karp

For the past 15 years, Tom Engardio has been involved with new product development at lens manufacturer Signet Armorlite. Drawing on his training as a chemical engineer, Engardio has concentrated on the area of lens materials and process development, including Signet’s RLXLite, EvoClear 1.56, EvoClear 1.6, and Corning SunSensors.

Recently, Engardio served as a technical contributor and team leader in the development of Signet Armorlite’s new Kodak InstaShades lens, which features proprietary “MultiMatrix” technology. L&T spoke with him about the challenges involved in creating this high-performance photochromic.

How did Signet Armorlite determine that consumers need a faster changing photochromic?
During the time Signet Armorlite has been producing and selling photochromic lenses, we have had the opportunity to learn from focus group surveys, our Signet Armorlite lab partners, our doctor advisory board and the subjects of our own wearer studies. Two items were of prominent interest to photochromic wearers: faded transmission and fade rate. This is not to imply that there weren’t other desired property improvements, but these were the two we thought were very important to the consumer and we could address from a technology perspective.

What were your goals in developing the lens?
The goals were numerous since we have to consider three different customers for the product. The final consumer wants a durable, good looking lens that darkens outdoors and fades rapidly upon returning indoors. The laboratory customer desires a lens that can effectively processed under a variety of conditions to meet a given prescription, accept various treatments and be edged and mounted in a frame. The Signet Armorlite lens manufacturing operation wants a process that will allow them to make quality lenses in high volumes with good yields.

How did you incorporate feedback from customers in the development process?
Our doctor advisory board and lab partners were exposed to our initial development product early on. Their input helped validate some of our underlying marketing assumptions and photochromic direction. Later, lab partners were given lenses to evaluate processing. Their feedback was important to determine how the lens would behave in the laboratory environment.

At what point in the development process did you know you had a unique product?
We knew pretty well at the beginning that our product was going to be different. Our concept was to use specialized materials best suited for their specific applications. That is, the multiple matrix approach would be used to optimize lens properties.

What is MultiMatrix technology and how does it make a better photochromic lens?
MultiMatrix technology refers to the three polymer networks that make up the lens: the optimized photochromic matrix, the lens body composition and the hard coat. All three are covalently bonded for excellent adhesion characteristics. This technology allows each to perform its specialized function in the lens, such as allowing for a faster fading photochromic, without compromises that might otherwise occur if the lens body and the photochromic matrix were the same.

What areas of its broad expertise in lens technology did Signet Armorlite tap into to develop InstaShades?
For the past several years, Signet Armorlite has developed its capability to develop new lens materials and processes such as those used for our EvoClear products. The photochromic composition development was new to us, but fortunately we have some very talented people in R&D and we were able to develop both the measurement capability and the photochromic matrix technology we were looking for.

What’s the next technological hurdle in photochromics?
Significant improvements in photochromic technology have been made over the past few years. The faded and darkened states of the major products have improved as has photochromic lifetime. I think these characteristics, as well as speed of change, will continue to be gradually improved in the coming years. The effective application of photochromics in other popular lens materials will also be an area of development.