|Identity lenses are available in the U.S. from Pro Fit Optix in three designs—Standard, Outdoor, and Office.|
Each manufacturer has its own approach to designing and producing lenses digitally. Progressive additional lenses (PALs) produced using the free-form process of digital surfacing have taken our business by storm. This technology gives manufacturers new tools to design some pretty sophisticated PALs, and each company has a unique perspective on how to customize its lenses to the patient, the Rx, the position-of-wear, and the frame dimensions. Here’s how some of the major lenses on the market are designed.
SHAMIR AUTOGRAPH II
Using Direct Lens Technology®, Shamir Insight, Inc. produces a back-surface design that brings the progressive optics closer to the eye, providing up to 20% wider fields of vision in all zones. Each customized Autograph II® PAL is accurate to within 1/100th of a diopter (0.01D).
The Autograph II lens with FreeFrame Technology™ also adjusts the lens’ design, zones, and zone placements so that they are suited for the frame the patient has chosen. For example, the lens design dynamically adjusts the corridor length and moves the reading zone to the most optimal position in the frame, retaining the full reading power.
To further fine-tune each Auto-graph II lens, Shamir incorporates As-Worn Technology™ by taking three additional, personalized measurements from the patient—pantoscopic tilt, panoramic angle (also
|A virtual computer simulation technique called Balanced View Control eliminates peripheral swim and skew distortion in HOYALUX iD lenses.|
known as face-form or wrap), and vertex distance. These measurements further compensate the Rx for the frame as it’s worn. With fitting heights starting as low as 11mm, you can fit the Autograph II into just about any frame in your office.
Developed by HOYA VISION CARE, North America, and first introduced in the HOYALUX® iD™, iD LifeStyle™, and iD LifeStyle cd lenses, the patented Integrated Double Surface Progressive Lens technology locates the vertical progressive components on the front surface of the lens and positions the horizontal progressive components on the back surface. The placement of the vertical progressive component on the front reduces vertical eye rotation, while placing the horizontal component on the back improves the width of all viewing zones.
Separating the two components controls magnification factors and reduces unwanted astigmatic errors. The separated design properties are restructured according to a virtual computer simulation technique called Balanced View Control to eliminate peripheral swim and skew distortion. This keeps the world viewed through the lenses flat and eliminates that rocky motion patients complain about.
To accommodate the broadest range of frame styles, the HOYALUX iD and iD Lifestyle cd lenses have a minimum fitting height of 14mm, while the iD Lifestyle offers an 18mm height. This variety accommodates most frame sizes and fitting situations.
VARILUX PHYSIO ENHANCED
|FREE-FORM ALL ON THE WEB While some labs provide a little resource material for their accounts, Luzerne Optical Laboratories, Ltd. offers a full array of lens information on its Web site, including material availability, lens cutout/progressive addition lens centering charts, photochromic options, high-index materials, and anti-reflective treatment availability and compatibility. You’ll also find information regarding minimum fitting heights, Transitions® options, and the power availability of free-form-produced lenses.
Expert Optics Inc. also has a great Web site. This lab offers products from Shamir Insight, Inc.; Essilor of America, Inc.; and Carl Zeiss Vision Inc., providing the latest in free-form-generated lenses. Its Web site also features a useful inventory management system along with some other laboratory “faves” such as LensStock.com (a way to order stock lenses at a competitive price). This site has full support service for free-form lenses and offers continuing education for both optometrists and opticians.
Created using the next generation of lens design technology that Essilor of America, Inc. calls W.A.V.E. Technology 2™, the Varilux Physio Enhanced™ PAL takes on difficult visual conditions such as low light, night driving, higher prescriptions, and strong cylinder powers as well as being able to handle simpler, everyday ammetropic Rx’s. In fact, Essilor reports that the lens maintains 93% of sharpness, even in low-light conditions.
This new level of wavefront optics more efficiently manages higher order aberrations in the lens, which go beyond the simple spherical and cylindrical errors eyecare professionals are familiar with and were previously uncorrectable using conventional design and surfacing techniques.
Varilux Physio Enhanced cleverly takes into consideration the patient’s pupil diameter as a function of the design. It does this by considering the patient’s age, working distance, lighting conditions, and the patient’s Rx, and it adjusts for the pupil diameter at different points on the lens for design purposes. These individualized parameters enable the lens’ software to adjust the lens so that it is ideally customized for how the patient will use it. Fitting heights range from 14mm to 25+mm.
Both the near and intermediate viewing zones in Supercede and Supercede Ws Internal Free-Form Lenses from Seiko Optical Products of America, Inc. feature advanced aspheric compensation. This technology optimizes the performance of the lens in the “as-worn” position, which means that it takes into account eye rotation and unique optical measurements relative to their visual axis and the lens’ optical axis. The Supercede is a “soft” design that is ideal for active first-time PAL wearers who need a wider intermediate area. It is a good choice for low-to-medium add powers and has a minimum fitting height of 16mm.
Supercede Ws lenses have a harder back-surface design that is ideal for frames with a narrow B measurement, seasoned PAL wearers, medium-to-high add powers, and for people who work on computers or do other closeup activities. Supercede Ws lenses come with minimum fitting heights of 14mm and 16mm.
When you think of Switzerland, you might envision chocolate, the Alps, precision timepieces, and
|Seiko’s Supercede Ws design is available in ultra-high-index 1.74 material, among others.|
|Shamir Autograph II lenses use Direct Lens Technology to produce a back-surface design that brings the progressive optics closer to the eye.|
cameras. But this country also has another precision product, ophthalmic lenses. Identity™ lenses, available in the U.S from Pro Fit Optix, offer three designs—Standard, Outdoor, and Office. Each is available in three minimum fitting heights of 16mm, 18mm, and 20mm, creating nine choices overall.
Identity lenses use free-form design and surfacing technology to achieve their features, which include wider zones at all viewing distances. One way this is achieved is by placing the progressive optics on the back surface of the lens. Free-form design technology also enables the lens to better reduce aberrations, which translates into clearer, sharper vision for the wearer.
Now that you have the inside story on how some of these lenses are designed, take the opportunity to try them. You and your patients will be glad that you did.
Sharon Leonard is a licensed optician and contact lens practitioner in the Syracuse, NY, area.
WHERE TO FIND IT
Carl Zeiss Vision Inc.
800-358-8258 • zeiss.com/lenses
Essilor of America, Inc.
800-542-5668 • essilorusa.com
Expert Optics Inc.
800-892-0097 • expertoptics.net
HOYA VISION CARE, North America
877-528-1939 • hoyavision.com
Luzerne Optical Laboratories, Ltd.
800-233-9637 • luzerneoptical.com
Pro Fit Optix
866-996-7849 • profitoptix.com
Seiko Optical Products of America, Inc.
800-235-5367 • seikoeyewear.com
Shamir Insight, Inc.
877-514-8330 • shamirlens.com
|FIVE FREE-FORM TRENDS Free-form is here to stay and will take over from traditional progressives, according to one of the technology’s early adopters, Ralph Cotran, co-owner/vice president of US Optical in East Syracuse, NY. Here are five trends from his perspective:
1. In about five years, all traditional progressives will be extinct, minimal, or reappear with the same name but with free-form variations. Designs that are already very good can only be enhanced by free-form manufacturing and customized designs. Is it a better progressive? Absolutely. Does it cost more? Yes, but not that much more!
2. We also see an increase in premium lenses with accurate facial measurements, customized even more than the first generation of free-form. Shamir’s Autograph® II and the Zeiss Individual™ allow for additional measurements and customizing the progressive to the patient’s face by accounting for unique individual measurements such as face-form angle, pantoscopic tilt, and vertex distance.
3. In this economy, value is where it’s at. The Seiko Succeed Internal Free-Form™, the newer Seiko Supercede Internal Free-Form™, and Shamir Element™ are excellent value choices for patients to upgrade to the newest technology.
4. Free-form solves some old industry problems. The Shamir Autograph Attitude™, for example, is an excellent solution for wrap frames both in free-form progressive and single vision. Even more of these are on the horizon.
5. We see a strong push toward branding single vision free-form lenses. This has huge potential and will work if patients are educated about the benefits and if the costs are reduced.