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PAL manufacturers continue to advance technology
Contact Lenses and Eyewear
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Today’s progressive-addition lenses (PALs) are designed to meet the varied needs of presbyopes by offering maximum adaptability and fitting options. As this lens technology advances, companies are fine-tuning their products by eliminating or reducing previous challenges. These products allow the presbyope to maintain appearance with fashionable lenses as well as an active lifestyle with improved acuity.
Varilux Physio 360°
Robert Davis, OD, a practitioner from Pembroke Pines, Fla., prescribes Essilor of America’s (Dallas) Varilux Physio and Varilux Physio 360°. “We present the Varilux Physio or Physio 360° as our lead lenses for all patients who are presbyopic,” he told Primary Care Optometry News in an interview. “They work so well, patients adapt easily to these lenses.”
With earlier progressive lens designs, emmetropes, hyperopes and first-time wearers especially may have had difficulties due to higher-order aberrations. One of the reasons for the difficulties is that all older types of progressive lenses caused coma, a higher-order aberration, Dr. Davis said. Modern manufacturing techniques have eliminated higher-order aberration in both Varilux Physio and Physio 360°. Dr. Davis said he prescribes either Physio or Physio 36° to 80% of his patients. He uses the Physio 360° for patients with powers higher than ± 2 D or patients with greater than 1.5 D of astigmatism.
Using the patented Wavefront Advanced Vision Enhancement (WAVE) process technology, Physio 360° is able to manage complex surface designs, according to information from the manufacturer. The lens is designed using a proprietary computer model to map the backside design for each prescription so that it perfectly aligns with the front side of the lens design. The design is applied with a patented 360° Digital Surfacing process.
This precision adds to the benefits experienced by patients and noted by eye care practitioners. “Because you are eliminating higher-order aberration with the WAVE technology, patients are seeing better at night,” Dr. Davis said. “Patients report to me that they can see sharper, read street signs quicker and are more comfortable driving their car at night.”
For patients who use computers, Dr. Davis has noticed that the increased intermediate area of this lens allows for easier viewing of the screen. “Reading tends to be sharper with this lens as well, because the optics are more precise, sharper than previous progressive lenses,” he said.
Dr. Davis said the primary challenge in fitting this lens is a matter of educating patients and pointing out potential issues. “The challenge, like any progressive, is the learning curve, especially for patients who have never worn progressive lenses,” he said. “Many patients adapt immediately to the lenses, but some may take a day or two to be perfectly comfortable with the lens. So, as long as you educate the patient ahead of time and tell them what to expect, there will be very little problem.”
Kodak Unique
Signet Armorlite’s (San Marcos, Calif.) latest PAL design is the Kodak Unique progressive. This progressive is designed to automatically customize to the patient’s spectacle prescription using proprietary production technology. The lens fit height is as low as 13 mm, which broadens patient’s frame options.
According to information from the manufacturer, Kodak Unique is customized using Vision First Design technology that synchronizes the front and back design. This technology helps patients who have either never worn progressives or wore traditional bifocals adapt easily.
“I have had many patients who wore trifocals for many years be able to switch into the Kodak Unique easily. It’s just amazing,” Marla Moon, OD, said during an interview with Primary Care Optometry News.
Dr. Moon, based in State College, Pa., has been increasing her use of the Kodak Unique since its introduction in June 2006. “Probably 50% of our progressive use is now with the Kodak Unique lens,” she said.
Dr. Moon’s credits this lens with easy adaptation, wider reading area and little to no distortion in the periphery.
The price of this premium lens is one example of the challenges met by Dr. Moon. “I introduce it to patients by giving an up-front, first-time discount, which helps,” she said. “I really believe in this product. I usually do not get patients that go to commercial facilities looking for a price discount. Our patients come looking for a premium product at our practice.”
Gradal Individual
The most advanced PAL offered by Carl Zeiss Vision (San Diego, Calif.) is the Zeiss Gradal Individual. This lens uses the latest in free-form technology to create custom lenses, applying the design, in most cases, to the front and back of the lens, according to company literature. This lens has a minimum fitting height of 18 mm, but the Gradal Short i version has a fitting height of 15 mm.
The Gradal offers customization for all aspects of a patient’s prescription, rather than using a semi-finished lens. Both Individual and Short i are customized for the vertex distance and pantoscopic angle of the individual’s chosen frame, allowing greater clarity in the as-worn position.
The benefits of Gradal individual include greater areas of clear vision and a reduction of unwanted astigmatism.
Hoyalux iD
Hoya Vision Care (Lewisville, Texas) manufactures the Hoyalux iD, the only integrated double surface progressive lens that fully integrates the advantages of aspheric front and back surfaces using Hoya’s patented Free-Form technology.
This lens reduces the occurrence of wavy effects from looking at the floor, walking down steps or in oblique directions, according to information provided by the company. This is achieved using Balanced View Control principles with Skew Deformation Index calculations.
The lens integrates two progressive aspherical surfaces that provide optimal aspherization in all directions, limitless visual sharpness, seamless interaction between near and far images as well as expansion of the free field of view.
Hoyalux iD has a 14 mm minimum fitting height.
Autograph
Shamir Insight Inc. (San Diego) recently introduced Autograph, a PAL that focuses on precise personalization. This lens is based on Shamir’s comprehensive lens design and production methodologies: EyePoint technology, back surface design, Prescriptor software and free-form technology, according to company literature.
EyePoint technology is designed to reproduce the human eye at every angle of vision and optical zone.
The back surface design brings the patients’ eyes closer to the lens design. This method, in effect, allows for an increased panorama and a wider field of view for the patient, according to the company. Prescriptor software increases the efficiency of lens production by capturing the patients’ personalized information and then selecting the appropriate lens design file.
Freeform Technology was formulated as a way to progress from lenses designed to meet the average to a more personalized method of PAL lens production. Until recently, semi-finished PALs were created in a limited number to meet the needs of average patient measurements. Shamir’s Freeform Technology bases production of PALs on an individual’s specific parameters, thus optimizing the design. Shamir has eliminated the need for molds so that each lens is produced within 0.01 D of the exact design and prescription.
Illumina
Vision-Ease (Ramsey, Minn.) has developed Illumina using fifth-generation design techniques. These lenses are designed with the unique needs and lifestyle of the presbyopic patient in mind.
According to information from the company, Illumina offers a wide reading area and softness, while maximizing viewing in all distances. The lens is suitable for everyday use and has an excellent adaptation rate. The 17-mm fitting height makes it suitable for most lens designs.
For more information:
- Robert Davis, OD, can be reached at 1732 University Dr., Pembroke Pines, FL 33024; (954) 432-7711; e-mail: eyesail@mindspring.com.
- Marla Moon, OD, can be reached at 428 Windmere Dr., State College, PA 167801; (814) 234-2015; e-mail: drmoon@nittanyeye.com. Dr. Moon has no direct financial interest in the products mentioned in this article, nor is she a paid consultant for any companies mentioned.
- Carl Zeiss Vision Inc. can be reached at 10590 West Ocean Air Dr., Ste. 300, San Diego, CA 92130; (800) 358-8258; www.zeiss.com.
- Essilor of America Inc. can be reached at 13515 N. Stemmons Fwy., Dallas, TX 75234; (800) 820-2020; www.EssilorUSA.com.
- Hoya can be reached at 3400 Edison Way, Fremont, CA 94538; (510) 252-8370; fax: (510) 490-1988; www.hoyavision.com.
- Shamir Insight can be reach at 9938 Via Pasar, San Diego, CA 92126; (877) 514-8330; fax: (877) 285-4863.
- Signet Armorlite can be reached at 1001 Armorlite Dr., San Marcos, CA 92069; (800) 759-4630; fax: (760) 471-6255; www.signetarmorlite.com.
- Vision-Ease Lens can be reach at 7000 Sunwood Dr. NW, Ramsey, MN 55303; (800) 328-3449; fax: (800) 289-5456; www.vision-ease.com.