Patient Benefits With Trivex Lens Material
Patient Benefit-Thin and Light
When compared to CR-39 monomer, lenses made with Trivex material are up to 15 to 20 percent thinner and always about a third lighter. An aspheric design will further reduce thickness and weight. While there are other higher index materials that can make lenses even thinner, lightness depends on final lens volume and its specific gravity. Some high-index materials have much higher specific gravities so the weight savings when compared to Trivex material is less than you might think. While the highest index lens of equal power is another 15 to 20 percent thinner, within the core range, lenses made with Trivex material are still 10 percent lighter. For the core range of lens prescriptions (-3.00 to +3.00), having a lighter lens is always a selling benefit. Vision Watch patient surveys always report that patients value the lightness of their spectacles.
Patient Benefit-Clear Vision
Material choice also affects the clarity of vision. A lens’ clarity is a product of Abbe, glare-free (anti-reflective) coating and the type of lens design used. Prism, off-center in prescription lenses, creates power errors and blur, the result of chromatic aberration and the lens design. Manufacturers work hard to create lens designs that reduce off-center power errors but the material still contributes clarity based on its Abbe. The higher the Abbe, the less chromatic blur. The result is a larger, clearer field -of-view (for the same prescription, material-to-material).
CR-39 material and glass lenses have the best Abbe. To support a choice of Trivex material as a replacement for CR-39 material, lens clarity should be equivalent. After all, crisp vision is an expectation of your patients, not something that you sell as an added benefit.
Abbe values are a relative measure of clarity and are not linear. Trivex material has an Abbe value of 45, which produces lens clarity virtually equivalent to CR-39 material.
Patient Benefit-UV Protection
UV radiation is a recognized contributor to the formation of cataracts, as well as pinqueculae, pterygia, keratitus, wrinkles and skin cancers. As a result, lenses sold in spectacles should always provide 100 percent UV protection. Any choice for an everyday lens material must provide 100 percent UV protection. CR-39 monomer, depending on specific lens manufacturer processes, absorbs between 85 to 90 percent of UV radiation while Trivex material absorbs 100 percent. While a UV dye can be applied to CR-39 material for added absorption, this dye can compromise the long-term adhesion of anti-reflective coatings and result in delamination. Therefore, it is more practical to choose a material that provides 100 percent UV protection without additional processing. Every lens made with Trivex material automatically provides protection from the effects of UVA and UVB radiation.
Patient Benefit-Impact Protection
According to The Bureau of Labor Statistics (BLS), almost 70 percent of the eye injuries studied occurred from falling or flying objects, or sparks striking the eye. The best way to prevent eye injuries is to always wear the appropriate eye protection. Since no one can predict when they will need eye protection, it makes sense to have eyewear, even everyday spectacles that provide impact resistance at all times. While it may be easier to bring up the subject of impact resistance when talking about kids’ spectacles or sport- specific spectacles, the truth is that everyone needs to protect their eyes and their vision, all the time.
By providing patients with an everyday lens that offers extreme impact resistance, you are making sure that their eyes receive the best protection no matter the activity. Providing this protection is even more important today, when patients are less likely to purchase more than one pair of glasses due to financial reasons. This means they are more likely to wear their everyday glasses while playing sports, working in the yard or around the house. Lenses made with Trivex material have 62 times the impact resistance of ordinary plastic lenses.
One office uses this statement to get across the message of eye protection for everyday lenses: “Our office recommends Trivex material as our standard lens material of choice because it provides the visual armor to protect your eyes from UV light, while providing the ultimate in impact resistance, no matter that you are doing.”
You are the reason that customers purchase since almost a third of Vision Watch survey respondents report that the most important reason for their purchase was that it was ECP-recommended. You are a trusted eyecare advisor; use your power to deliver the best bundle of benefits.
In Part Three of this series we will examine the benefits of Trivex for frame choice as well as ways to recommend Trivex lenses.
* Both CR-39 monomer and Trivex material are manufactured by PPG Industries.
Mark Mattison-Shupnick, ABOM, is currently director of education for Jobson Medical Information LLC, has more than 40 years of experience as an optician, was senior staff member of SOLA International and is a frequent lecturer and trainer.