20 20 April 2012 : Page 110
HIGH PERFORMANCE, HIGH WRAP, SPORTS PRESCRIPTION SUNWEAR .2 02 0mag .c o m /C E ww ed prism is limited m to about 0.25 for the h area of mid-periphery. This provides for e wider fields of clear view. FAR-PERIPHERY VISION In an evolutionary way, prehistoric man had to know when a predator was lurking in the shadows, just out of the field of view. As a result, the visual system evolved to make the periphery of the retina extremely sensitive to small amounts of changing light and the ability to turn the eye to confirm a threat. It’s the same for the modern athlete. For a cyclist, competitors in the far periphery about to make a break from the peloton, must be “seen” as soon as possible to ensure that a like reaction occurs if necessary. So, the best far peripheral clarity would be ben-eficial. Clarity of motion detection would be improved if blur (astigmatism and power error) and distortion are corrected at the angles of the far periphery. Figure 5 illustrates the cylinder and power error of an 8 base, high plus lens (upper) versus the same lens done as an FIGURE 5 110 • April 2012 20/20 w OAKLEY TRUE DIGITAL Central View FEATURES Wide fields of vision DUAL PERIPHERAL TECHNOLOGY Mid Periphery Low prism imbalance Far Periphery Low unwanted astigmatism Better motion detection BENEFITS Crisp, clear detailed vision Better large image recognition This results in the lens protruding from frame front, changing the angle of the lens and the effect of the Rx. More importantly, it changes the way the patient receives their new glasses; differently from the way they expected their eyewear to look. For the newer step bevel and fluted lens designs, specialty-edging systems are required. Oakley True Digital (lower). Using the ellipse as a suggested frame shape, it can be seen that there is significantly more blur for the spherical lens. The Oakley True Digital lens is significantly less blurred for improved far peripheral vision. By reducing the errors at these angles and reweighting the way that the periphery affects vision, both eyes can provide the right three-dimensional spatial cues. Therefore, more than just the axial-wrap-compensations are required when thinking about lenses that work for the athlete. Lens-es that correct the periphery can outper-form an ordinary 8 base added to wrap frames. These lenses can provide a better recognition of peripheral objects and move-ment, and when combined with sports training, practice and experience, wearers can improve sports performance. Lastly, for better lens cosmetics, lenses are manufactured with a thickness reduc-tion prism. This insures that lens thickness at the frame top and bottom is the same. This has been a typical improvement in progressives in standard lenses, now used also for wrap eyewear. PUTTING IT ALL TOGETHER Oakley True Digital and Oakley Dual Peripheral Technology capitalize on a pro-prietary Oakley frame database to accu-rately deliver the right digital lens designs in a patient’s prescription. Reconstructing the central Rx and redesigning the periphery for the frame chosen for the way that the frame fits, provide an optimized solution in high performance, high wrap sunwear. There are few risks in dispensing an authentic product since the hard issues of frame measurements are known. Two pre-scriptions are returned to the optician so that lens verification of the reconstructed Rx is easy. Verify the Rx using the reconstructed Rx supplied by the laboratory. Be sure to include the prism. At the compensating prism, dot the PD at the prism values shown and verify the PD. With the prism the PD will be the same as the patient’s. CONCLUSION Oakley True Digital reconstructs the central prescription for the best vision for any wrap angle. Oakley Dual Peripheral Technology ensures sharper peripheral imaging and motion detection, critical for the split second decisions of any athlete. The result is a high wrap prescription sunglass that delivers more than crisp acuity; but a clear periphery and the fluidity of vision across the lens to best meet anything the sport throws at you. Make authentic wrap prescription sunwear an integral part of every lens solution for any athlete or sports enthusiast that visits your office. Oakley True Digital is a benefit for not only the sports-minded but any patient looking for the best possible optics. ■ LENS EDGING Wrap frames also place special demand on edging. The extreme angles at the lens periphery as well as the position of the nose pad may get in the way of the lens edge; standard bevels do not work. For mid to high minus and plus prescriptions, lens thickness requires steeper bevels and the rear lens wall must be angled correctly to avoid the frame behind the bezel. One solution for plastic wrap frames was to place the bevel at the back of the lens.
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