PPG’s newest, Tribrid material is recommended for moderate to strong prescriptions and grooved and three-piece rimless frames.
Long known for innovative lens materials, PPG’s latest is Tribrid material, which is lighter, stronger and clearer than other high-index lens materials. Introduced in North America this year, Tribrid material’s 1.60 index of refraction gives eyecare professionals (ECPs) and patients alike a viable alternative to 1.67 and 1.74 high-index lenses with crisp optics, an Abbe value of 41, lighter weight and superior impact resistance.
PPG recommends Tribrid material for moderate to strong prescriptions ranging between approximately -3.00D to -7.00D and +3.00D to +7.00D. Patients enjoy a thinner lens than standard 1.50 plastic lenses and sharper optics when compared with polycarbonate lenses.
Patients also notice a significant reduction in weight due to Tribrid material’s specific gravity of 1.23g/cm3 as opposed to a 1.74 high-index lens at 1.47g/cm3 or a 1.67 high-index lens at 1.36g/cm3. Tribrid lens material is almost ten times stronger than conventional standard plastic and up to five times stronger than traditional 1.60 and 1.67 index lenses, according to results from Gardner Impact Test data.
ECPs can comfortably recommend Tribrid lens material for patients who enjoy grooved and three-piece rimless frame products. In initial ISO 12870 frame endurance and COLT’s lateral bridge stress frame tests, Tribrid lenses outperformed 1.60 and 1.67 lenses with respect to chips and cracking during fabrication and frame adjustment. The material modulus allows the three-piece mountings to remain tight during normal wear, similar to the three-piece performance of Trivex material. Dispensers can adjust nosepad angles and temple spread using conventional hand tools and good technique without fear of lens cracking or splitting.
Superior impact resistance when compared with other high-index lenses, lightweight and crisp optics make Tribrid lenses an excellent choice for patients with an active lifestyle who are presbyopic and would like an upgrade from traditional high-index offerings. For additional eye health protection, Tribrid material blocks 100% UVA/UVB. In addition, the material accepts upgrades such as front and backside anti-reflective coatings. Photochromic options will be available in Tribrid material in the near future.
RETAILING EDGE FOR ECPS
Adam Cherry of Cherry Optical, a large independent wholesale lab in Green Bay, WI, reports that his ECP customers promote Tribrid material as a unique premium product and charge accordingly. In addition, the uniqueness of the product allows the ECP to market a lens not readily offered by big box retailers and discounters.
THE ADVANTAGES OF TRIBRID MATERIAL
Tribrid material represents a state-of-the-art, high-index lens material that can be readily added to an eyecare professional’s offering of premium lens products. Here are some advantages:
• Lighter weight when compared with conventional high-index lenses
• Improved impact resistance—up to five times that of traditional 1.60 and 1.67 and almost ten times that of conventional standard 1.50 plastic lenses
• Crisp optics with an Abbe value of 41
• The relative tensile strength of Trivex material with respect to frame selection, lens fabrication and frame adjustment
• Compatible with lens upgrades such as anti-reflective treatments
• 100% UV blocking
VIEW FROM THE ECP
Amy Schoening from Marsh Family Eyecare in Oshkosh, WI, reports successful results with Tribrid lens materials in the dispensary. Patients enjoy the lens appearance due to flatter base curves and significant weight reduction. In addition, veteran high-index wearers notice a significant higher optical clarity in the +5.00D to +6.00D range. The practice prices the Tribrid option in line with Trivex and traditional high-index lenses, thereby giving patients a wide range of lens choices. Lenses are edged in-house on AIT/WECO edgers with no special lens-cutting steps required other than activating the machine’s high-index settings.
Richard W. McCoy, LDO, ABOC, NCLEC, is an opticianry instructor at Hillsborough Community College in Fort Myers, FL.