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TRIVEX Material
Still a New and Growing Lens Category

By Mark Mattison-Shupnick, ABOM

Release Date: March 1, 2014

Expiration Date: April 1, 2015

Learning Objectives:

To update the ECP on changes and adoption practices for a lens material that is capable of being the overall lens platform including:

  1. Why lens material is the foundation on which all lens attributes are formed.
  2. A material category's attributes and adoption a decade after initial introduction in a market that is slow to change.
  3. Learn the broader everyday uses of Trivex material.

Faculty/Editorial Board:

Tim Slapnicher 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.

Credit Statement:

This course is approved for one (1) hour of CE credit by the American Board of Opticianry (ABO). Course STWJH036-2
This course is supported by an educational grant from PPG INDUSTRIES, INC.


fig1Trivex material's development has been consistent with the way new technologies build sophistication into products. In the past, a lens material had to be more closely matched with the prescription and the end results wanted. This is no longer the case. By bundling benefits through advanced lens material technology, a new lens category has taken shape and continues to grow. The growth of the Trivex material category has coincided during a shift in consumer purchase preferences and behaviors. In a 2012 online survey of eyeglass wearers (Fig. 1) conducted by Lightspeed Research, more than 38 percent of respondents said that "a combination of lens attributes" was how they decided on lens material during the purchase. That's not surprising since one of the results of the 2008 to 2009 recession made value the most important deciding factor in a customer's purchase. When combined with an ECP's recommendation, that accounts for 60 percent of the decision. Therefore, understanding what makes Trivex material a highly valued, sophisticated bundle of benefits and how you can incorporate it into your lens recommendations will provide your patients with more value and greater satisfaction.

MATERIAL ATTRIBUTES AND PREFERENCES

The lens material and its characteristics become the foundation on which all lenses and their final properties are built. A material's attributes form the final product that is delivered to the patient. However, no lens is the result of only one of its properties (index or impact or specific gravity, etc.). In fact, choosing a lens material because of one attribute, such as index, can often create a lens that isn't what the optician or the patient expected. Lens attributes work in combination. Consumers do have preferences, and from VisionWatch, The Vision Council collects more than 100,000 eyewear consumer opinions annually. For the 12 months ending September 2013, lightness (comfort) and scratch resistance (value and durability) combined were the most important of attributes reported by more than 60 percent of those surveyed. In fact, lightness or comfort becomes a much larger concern for those over 55 when eyewear is required and worn more continually. Therefore, the interaction of a lens material's properties make the final lens. They are more important that any one attribute.

A lens' final thinness, most important to an additional 12 percent of respondents, is determined not only by index, but more importantly, by the material's impact resistance (for the frame style, size and shape chosen by the patient). The extreme impact strength of Trivex material significantly exceeds FDA impact requirements. This allows minus lenses with thinner centers to be sold. Unlike lenses made with CR-39 monomer (from PPG Industries), which are produced to 2.0 mm centers, lenses made with Trivex material are produced to about 1.2 mm centers. This 0.8 mm reduction in thickness is possible in all but the powers near plano. In addition, that also means an equal reduction in edge thickness of almost a millimeter. When combined with the index of 1.53, lenses are thinner yet. In plus lenses, edges can be made thinner, since the material is not prone to flaking or chipping (due to tensile strength, notch sensitivity) especially when grooved.

This benefit of lens thinness is typically combined with lightness in the sales process. That's because thinness reduces lens volume and creates the final weight of the lens. However, the real lens weight is a function of volume and the material's specific gravity. In this case, Trivex material was engineered to be the lightest material (1.11g/cm3). In the same Rxs, lenses with Trivex material are always thinner and lighter than CR-39 monomer due to its index, extreme impact resistance and specific gravity.

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. VisionWatch patient surveys always report that patients value the lightness of their eyewear.

Patient Benefit—Clear Vision: Material choice also affects the clarity of vision. A lens' clarity is a product of Abbe, glare-free (antireflective) 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 eyewear 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 glasses that provide impact resistance at all times. While it may be easier to bring up the subject of impact resistance when talking about kids' eyewear or sport- specific eyewear, 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 both UV light, while providing the ultimate in impact resistance, no matter what you are doing." You are the reason that customers purchase since almost a third of VisionWatch survey respondents report that the most important reason for their purchase was that it was ECP-recommended (Fig. 2). You are a trusted eyecare advisor; use your power to deliver the best bundle of benefits.

FRAME CHOICE

Frame choice also drives material choice. Usually the patient will select their frames first and then the lenses. This can present a problem with some lens materials. Consider the combination of a plus lens and a grooved semi-rimless frame. Lenses made from CR-39 material flake or chip at the thinnest corner. Oftentimes, patients will return a pair of rimless glasses because of star cracks around the drilled holes or flaking at the edges.

Patient Benefit—Frame Choice Freedom: Lenses that retain their looks and safety regardless of frame style allow patients to select the frame of their choice knowing that the lenses will not be affected. By selecting a lens material that doesn't flake or crack, opticians can feel confident that no matter the frame choice of the patient, the lenses will be suitable for the frame.

Trivex material is unique in that it has extremely high strength and virtually no notch sensitivity. This means that the lenses won't develop edge flakes or chips, and when used for drilled rimless, won't star crack. This is particularly important in drilled polarized lenses. Polarization efficiency is affected by compression at the drill points. Choosing Trivex material solves many problems before they start by reducing breakage and remakes.

TARGET AUDIENCE

fig3Eighty-five percent of the U.S. population that requires vision correction is within the range of -3 to +3 diopters (Fig. 3), which means the majority of patients might not require a high-index material to achieve a thin lens. Trivex material will produce an equivalent or comparably thin lens for these prescriptions while also providing the patient with a more robust combination of lens attributes – optical clarity, lightweight comfort, impact resistance and UV protection.

WHAT TO SAY

When making a lens recommendation, include the patient benefits of the lens along with the lens attributes. The more "true-to-life" the description, the more it will resonate with the patient. Again from VisionWatch, you are in control of the lens' attributes because consumers report that their decisions are ECP-driven. Almost a third report that their most important reason for purchasing is their ECP's recommendation.

Suggesting a change to Trivex material as a replacement for CR-39 material might sound like this:

  1. I'm recommending lenses made from Trivex material because it delivers crisp, clear vision with exceptional optical performance.
  2. Your lenses will be ultra-lightweight, provid ing added comfort since Trivex material is one of the lightest lens materials available.
  3. This material automatically provides 100 percent UV protection and is unsurpassed in impact resistance and durability, meaning your eyes will always be protected.

PREMIUM OR EVERYDAY?

Should Trivex material be considered as a premium or everyday lens material? Perhaps this is the wrong question to ask. The correct question should be, "What is the best material for the patient's Rx and vision requirements?"

Remember, the Rx is the driver with the balance of lens properties completing the requirements. If a patient with a -2.00D Rx requires lightweight lenses and protection in a rimless frame, Trivex material may be the best solution especially if the patient had a bad experience with star cracks in a previous pair of rimless glasses. If the Rx is -6.00D and thinness is the number-one consideration, then a higher index material is probably the better choice for this patient.

Deliver the best eyewear for the patient, which includes being selective when it comes to recommending the lens material.

kidsTRIVEX MATERIAL FOR KIDS

Kids need sharp, precise vision for all they do. Their active and unpredictable lives also demand eyewear that provides the best strength and protection.

It's estimated that 80 percent of what children learn in their first 12 years comes through their eyes. However, children's eyes are underdeveloped. In fact, the crystalline lens of a child's eye is virtually transparent and offers very little protection for the retina. The eyes of a child under the age of 10, transmit over 75 percent of UV radiation compared with 10 percent in adults, ages 25 years and older.

Here are two scripts you can use to highlight the importance of quality lenses for kids:

"We only use lenses made with Trivex material that provide extreme protection from UV radiation and are impact resistant while delivering the best in clear vision for your child."

Or consider adding glare-free lenses and say, "Because children rely on their vision for learning, it is important that they have the most durable, non-glare lenses made with Trivex material. Non-glare lenses can eliminate headaches and tired eyes caused from white boards, computers and classroom lighting. In addition, since children spend more time outdoors, they are exposed to more glare and harmful UV rays. I recommend lenses that absorb 100 percent of the harmful UV rays. They are also available in photochromic lenses that change tint when your child goes outdoors and then changes back to clear when they come back inside."



TRIVEX MATERIAL FOR SUNWEAR? IT'S THE RIGHT CHOICE

"High velocity impact resistance" (Z87.1 that is) says it all. A lens material that can meet Z87.1 high velocity impact standards ensures that eye injuries are lessened, and your patient's vision will be protected. The wrap shape of many of today's sport sunwear also helps to reduce dust, dirt and wind from getting to the eyes. The steepness of the 8-base lens shape adds to the impact resistance structurally, while a polarized lens eliminates blinding glare. Since sunwear is worn outdoors during activities such as cycling, skiing, jogging, fishing and golf, the likelihood of eye injury increases with these types of activities. Providing your patients with sunwear made with an extremely impact resistant and UV-absorbing material like Trivex material in polarized and/or photochromic versions will provide the optimum protection for their eyes.

TRICKS OF THE TRADE

When converting from a well-known material like CR-39 material to Trivex material, there are a few tricks-of-the-trade that savvy labs and opticians have adopted to make their lives easier and the results predictable.

Let the lab choose the correct base curve, especially when lenses are digital or aspheric in design. This is extremely important since good peripheral vision through lenses is index, base curve, Abbe and position of wear dependent. Manufacturers have calculated the correct base curve to choose to provide best vision, and labs store those tables for lens choice when completing an Rx order. This is still true for digital lenses and the preferences of digital lens designers.

For the office that does its own edging: It is easy today to edge Trivex material since edger manufacturers have modified their systems to add Trivex material capability. Direct drive motors get instructions on speed and torque from a sophisticated internal software module by simply choosing the Trivex material mode. The drain that carries away waste material (swarf) has been increased in size so any heatinduced material "clumping" washes down the drain without a clog. Water, as coolant, also washes/cools the back of the grinding chamber so there is little effect from any heat generated.

For drilled rimless: Trivex material is the least affected by drilling, so it reduces or eliminates the possibility of star cracks or breakage. That same tensile strength and lack of notch sensitivity allows thinner edges on grooved semi-rimless since the groove wall is unlikely to chip or flake. In both frames styles, it reduces the number of remakes and improves patient satisfaction.

AVAILABILITY

Making a global change to a material that can be used every day requires good availability in the styles and designs you dispensed.

With the advantages of free-form manufacturing in the laboratory, virtually any of the newer optimized and/or personalized progressives and single vision lenses can be created in Trivex material. The latest generation photochromics (Transitions Signature VII lenses), polarized lenses (such as NuPolar Trilogy and NXT lenses) and blue-light blocking treatments (such as HOYA Recharge) are now available in Trivex material. Add the high quality scratch resistant and AR technologies that are widely available from multiple manufacturers, distributors and laboratories, and the opportunity for a new lens platform takes shape. Even frame manufacturers are beginning to experiment with the Trivex material platform as a lightweight, durable and unique frame material. Companies such as Monoqool and the Serengeti Genus collection are examples.

You'll find that Trivex material lenses are available in the latest designs and formats from: Augen, Essilor, HOYA, Kodak/Signet Armorlite, Nassau, NuPolar, NXT/Intercast, Seiko, Shamir, Shore, Transitions, Unity/VSP, X-Cel, Younger, Zeiss and others.

LEARNING TOOLS AND RESOURCES

As with any lens material, you'll find that there are best uses for Trivex material while other situations may call for a different material for a particular patient's needs. Your optical laboratory is a great resource for lens information and education.

Visit www.ppgtrivex.com for Trivex material availability from the manufacturers mentioned above. The Trivex material website has tips for processing as well as a complete e-learning module at www.ppgtrivex.com/education. Review other CE courses at 2020mag.com/CE for additional information about material choices and visit the Opticians Handbook (www.opticianshandbook.com) for up-to-date information about your best material choices.

CONCLUSION

Since the material is the foundation on which lens styles and designs are built, it's important to start with the best combination of lens material attributes to provide the most benefits for each patient.

By considering the interaction of lens attributes and material properties, opticians can offer a better choice for everyday eyewear for their patients. Consider replacing CR-39 monomer as the standard lens material with Trivex material and provide increased patient benefits.

**Both CR-39 monomer and Trivex material are manufactured by PPG Industries.