|Vision through a Varilux progressive with
W.A.V.E. Technology (above) is sharp and clear
when compared with an ordinary PAL.
Advanced software is key when fabricating digital lens designs for conventional frames as well as for popular wrap frames. The result is sharper central vision and a wider undistorted view, optimized vision that eyecare professionals (ECPs) now have many options for achieving.
Ocuco, a major supplier of software, provides wholesale laboratories and ECPs the computer software encompassing over 2,500,000 designs to effectively fabricate Rx’s. This comprises the largest lens database in the world. Ocuco is also a distributor of IOT, a major vendor of private label digital progressives and single vision lenses.
RX AS GOOD AS PLANO
Patients expect their Rx eyewear to perform equal to plano sunwear, according to ZEISS. A number of drawbacks to this are steep base curves required to match the base curve of the frame, optical issues including prism and diopter powers, off-axis aberrations and excessive edge thickness in minus powers.
To address these, ZEISS has introduced ZEISS CET (Cosmetic Edge Technology). By using advanced computer methods, blur and distortion are minimized and a significant reduction in edge thickness is achieved. This is prominent in Rx’s with strong negative powers with an edge thickness reduction of up to 30%. This equates cosmetically with going from a standard index lens material to a high-index option. Other benefits include compensations in lens design to negate the effects of prism, astigmatic and axial errors induced by extreme tilts. CET technology is available in a number of lens designs and material choices.
Other technology from ZEISS, Synchrony Curves represent an evolution in wrap lens design in which the lens profile and thickness are controlled by computer algorithms, resulting in a more usable optical area and cosmetics.
Technological breakthroughs continue as Shamir recognizes the active diverse lifestyle of eyeglass wearers with the creation of the Attitude III product line, engineered with four key concepts:
Eyepoint Technology III simulates real world images by using a reverse engineering program. This simulation results in a quality vision experience for the patient regardless of prescription or frame choice.
Natural Posture is a concept that helps make prescription lenses “user friendly” by taking into account the plus and minus powers of a patient’s Rx to allow for a natural viewing posture, while reading.
IntelliCorridor incorporates proprietary technology to control the power profile of each lens, thereby addressing the needs of sports and fashion eyewear requirements without compromising lens performance.
As Worn Quadro takes into account the parameters of the frame design and incorporates the data in the fabrication of the lenses. This is important because it considers the variables of pantoscopic frame tilt, panoramic angle and vertex distance.
The Shamir Attitude III lens offerings include single vision lens designs and progressives for sports and fashion. Finally, Shamir offers this lens product with extended base curve options, making them suitable for flat frame or wrap designs with no compromise in optical integrity.
|State-of-the-art measurement devices, such as the ABS Smart Mirror, are effective when presenting premium products such as wrap lenses.|
WRAP PALS AND SINGLE VISION
Essilor lens designers utilize Wave Technology 2 (Wavefront Advanced Vision Enhancement) in Varilux lens designs. This advanced technology identifies and eliminates distortion and customizes the wavefront correction to the patient’s needs. The patient enjoys sharper vision even in low light conditions by taking into account the change in pupil size in the initial lens design.
Advanced lens design is utilized in the Varilux Stylistic Progressive Sun Lenses and Stylistic Single Vision Lenses. Both progressive and single vision lens designs have the ability to accommodate high prescription requirements in a wide range of materials and lens options. In addition, both lens products can be fabricated with frame wrap angles of 0-30° to satisfy the diverse style choices demanded by patients.
ANY LENS, ANY MATERIAL
HOYA, using free-form technology, offers Array/Array Wrap lens designs. HOYA free-form options can be fabricated on the back surface of any semi-finished lens in any material. Benefits to the patient include a wider field of view over standard designs and material consistency for patients using multiple pairs of eyewear. Computer software calculates the appropriate prescription compensation for wrap frame choices.
ECPs should review a number of points before edging wrap lens designs in-house. Review the owner’s manual with respect to the capabilities of the existing edger to cut wrapped eyewear designs. If needed, contact the manufacturer with any issues of concern. Upgrade equipment as needed. Verify the accuracy of the lens cut to the patternless measurement parameters of the lens tracer and recalibrate as needed. As little as 1/10 mm error in bevel height can result in a lens never being fully secure in the chosen frame.
Access laboratory staff skills with respect to hand edging. On occasion, lens bevels need to be reshaped, reduced or moved in correlation with the frame/lens profile. Lab staff should practice as needed to sharpen hand edging skills to accommodate wrap lens designs. An important asset to the ECP is to always embrace the expertise of the wholesale laboratory partner when fabricating difficult wrap products.
|ANATOMY OF A WRAP LENS
Sophisticated digital lens designs require a choreography of precise measurements to ensure that the full potential of the chosen lens design is realized by the patient. High technology lenses that are customized to the patient rely on a number of key points.
VERTEX DISTANCE OF THE FITTED CHOSEN FRAME. The frame should be fitted to the patient taking into account any adjustments required for a personalized fit. When fitting state-of-the-art wrap lens designs, the ECP should be aware of recommended vertex distances and make adjustments accordingly when the distance moves out of the 12-13 mm default range or if the lens has a specific fitting distance.
PANTOSCOPIC TILT. A general rule of thumb for pantoscopic tilt is 10-12°. However, the ECP should review the fitting parameters of the specific lens chosen so the maximum optical benefit can be realized by the patient.
FACE FORM/WRAP ANGLE. Just as vertex distance is critical in fitting digital wrap lenses, face form or wrap angle of the selected frame is another critical parameter. Modern digital lens fabrication utilizes computer numeric control processes in which base and ocular curves can be optimized for an individual Rx. The Rx cannot be fully optimized without the wrap angle being included in the Rx calculations.
OPTICAL CENTER HEIGHTS. These should always be taken to avoid a prismatic effect should the patient’s line of sight deviate from the frame datum line, power in the 90th meridian becomes considerable or fabricating lenses with high indices of refraction.
FITTING CROSS HEIGHTS. When fitting patients with wrap progressive sport lenses, the fitting cross as relates to the corridor must always be taken. Although the standard fit is center pupil for dress eyewear, there can be variations due to the sporting activity or fitting parameters of the chosen lens.
WRAPPING IT UP
Sophisticated lens technology demands state-of-the-art measurement systems. To discuss the features and benefits of a premium lens product only to use antiquated measurement techniques not only demeans the product in the patient’s mind, compromises the crisp optics promised and calls into question the premium price point of the lenses, but it also opens the ECP to competitors who are more technologically savvy.
Examples of measurement technology are the OptiKamPad by OptiKam Tech Inc. OptikamPad makes use of iPad technology to provide ECPs with a precise tool to electronically capture measurements such as monocular PDs (far and near), fitting/seg heights, as well as personalized measurements such as pantoscopic tilt, vertex distance and frame wrap. In addition, all frame parameters are recorded for Rx calculation and/or compensation from one single frontal image. The patient is at the center of attention throughout the dispensing process as OptiKam can take up to four images of the patient with different frame choices and demonstrate the benefits of premium lens options.
Groundbreaking technology continues today with the ABS Smart Mirror system, from ACEP, a pioneer in measurement devices that invented frame selection systems in 1994 and added touch screen capability in 1997. A tablet-based device coupled with sophisticated augmented reality simulations provides the ECP critical tools in the advising/explanation process of today’s advanced lens designs and options.
|FOR MAXIMUM WRAP SUCCESS|
|1. Survey various manufacturers in regard to wrap lens designs/Rx capability.
Arrange a good, better.best scenario for retail pricing and selection.
|2. Be aware of lens and fitting parameters of selected lens designs, materials
and options available.
|3. Review dispensing fitting technology, staff knowledge and upgrade/train as
needed. When using electronic devices, make sure staff is consistent with
use of devices in the presentation of lens products.
|4. Review the dispensary lab for wrap lens fabrication capability and/or review
the wholesale lab partner for wrap lens expertise.
|5. Review dispensary frame inventory with respect to dress wrap frames and
wrapped sunwear designs, and adjust inventory accordingly.
LENS OPTIONS, TECHNOLOGY
After the initial lens selection has been made, the natural progression in patient care is to review lens options. There are many computer simulations available to illustrate the features and benefits of anti-reflective coatings, polarized sunwear, photochromic options and thickness simulations when comparing lenses with different indexes of refraction. These provide a superior presentation to the patient as opposed to crude drawings and scratched lens samples.
Major lens manufacturers recognize the importance of fitting technology as relates to lens design. An example of this is the i.Terminal 2 by ZEISS. In addition to critical measurements, this unit takes into account head rotation and tilt to assist the ECP in determining correct pantoscopic tilt for the selected frame.
Shamir adds a partner to the ECP’s life in the form of Shamir Arch. This is a downloadable app for Apple and Android devices that will immediately let the ECP know if the frame selected and lens choice are compatible. Instead of getting a call from the laboratory, the ECP gets immediate feedback on the frame/lens choice while the patient is still in the office and can make another series of frame choices.
Richard W. McCoy, LDO, ABOC, NCLEC, is an opticianry instructor at Hillsborough Community College in Fort Myers, FL.
WHERE TO FIND IT: ABS, Inc. • 888.989.4227 • smart.mirror.com • firstname.lastname@example.org // Carl Zeiss Vision, Inc. • 800.358.8258 • zeiss.com/lenses • email@example.com // Essilor of America, Inc. • 800.542.5668 • essilorusa.com // HOYA Vision Care, North America • 877.528.1939 • hoyavision.com • firstname.lastname@example.org // Indizen Optical Technologies (IOT) • 310.787.6649 • iotamerica.com • email@example.com // Ocuco Inc. • 800.708.1610 • ocuco.us • firstname.lastname@example.org // Optikam Tech, Inc. • 888.356.3311 • optikam.com • email@example.com // Shamir Insight, Inc. • 877.514.8330 • shamirlens.com • firstname.lastname@example.org