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Polarization has become a standard aspect of today's sun wear, but the technology has been around for almost 80 years. It was invented by Edwin Land and his Polaroid Company, hence the familiar name.
Polarized lenses are a superior alternative to traditional tinted lenses. The difference lies in the their ability to decrease horizontal or 'flat' glare that often reflects off vehicles, bodies of water, roads, ice, and other horizontal surfaces that patients face in their day to day lives.
A patient may express concern over the darkness of their lenses, and if they will be sacrificing any comfort by choosing polarized lenses. Thankfully, these lenses are available in a wide range of lens designs and materials, a patient can have the same hue intensity that they enjoy with the benefits of polarization.
The polarized component of the lens is made from a thin piece of polyvinyl alcohol film, on which energized iodine crystals were situated vertically. This alignment only allowed vertical light waves to pass through, while blocking the horizontal light, similar to Venetian blinds.
Originally, this thin layer was sandwiched between two layers of glass, and then the trio was laminated together. Although this provided a great alternative to the mundane world of sun wear, it was not with out draw backs.
One problem with this process is that the glass layers could crack easily. If a patient dropped their eye glasses, the result could be seeing the world through many pieces of glass held in shape by the lamination process.
Over time, as plastic resin and polycarbonate lenses became more viable options as lens materials, they replaced glass in the polarized lens sandwich. Although they were not prone to cracking, the lenses would delaminate, each layer pulling away from the others. This would present itself as a white area toward the edge of the lens. Over time, the opacity would expand over the entire lens, making them unwearable, and the patient frustrated.
A more modern method of manufacturing was developed, suspending the polarized layer (PVA) in a casting mold. This would allow the layer to be casted into the lens, eliminating the issue of delamination.
In both methods, the polarized layer was situated closely behind the front curve of the lens. This allowed the back side to be surfaced with out endangering the layer.
Polarized lenses can benefit anyone who encounters horizontal glare alone or coupled with bright sunlight. Like traditionally tinted lenses, polarized lenses are available in different shades for use in certain activities and tasks.
Fishing enthusiasts have used polarized lenses to look beyond the water and to the fish beneath it. Hunters opt for red or yellow lenses to achieve maximum contrast when staring down a target.
Polarized lenses in both gray and brown benefit those who spend time behind the wheel, whether for hours or minutes at a time. Transitions Drivewear from Younger Optics is one type of polarized photochromic lens, which changes color based on the light situation.
NuPolar® polarized lenses from Younger Optics are available in Flat Top 28 and 35, 7 X 28 trifocals as well as the Image progressive in CR 39 and polycarbonate.
Signet Armorlite offers several SA PolarShades® Lens choices. The digitally surfaced KODAK Unique Progressive is available in 1.67 index, PolyClear® and standard resin. The other options include the KODAK Precise® and Navigator® Progressives, as well as a single vision lens.
A line of photo chromic lenses is offered by TAG Heuer Avant-Gard Eyewear, in grays, browns, plums, blues and specialized colors for High Mountain and Water sports. The line is also optimized with flash mirror coatings.
To optimize the performance of polarized lenses, consider lens enhancements. Anti-Reflective coating on the back side will serve to eliminate back side reflections, including those caused by curvature deviations, such as wrap-around sun wear on an eight base.
Polarized lenses protect against both direct and reflected ultraviolet light. This provides more protection than tinted lenses. Mirror coatings are an increasingly popular addition to polarized sun lenses. Gone is the intense mirror that hides the wearer's eyes. Modern mirrored coatings allow the wearer's eyes but still reflect light. They are available in different colors, gradients, and intensities.
Some will decrease light transmission, making them a good choice for extreme lighting conditions. Others have beautiful colors, but do not decrease transmission as much, making them more suitable for a wider field of lighting conditions.
A functional lens can also be fashionable. Kbco is one of the premier polarized companies, offers 17 different colors, including photochromics and a silver flash mirror.
Polarized colors range from very intense to pale. A Venetian blind works best when made from a dense material. For the same reason, paler colors are going to have less polarization than their darker counterparts. This can be a benefit indoors, in office situations such as fluorescent lighting and computer monitors.
Many polarized lenses can be tinted to increase color intensity or to personalize it for the patient's needs. Since the heat used for tinting can affect various lens materials differently, it is important to consult the lens manufacturer for specific instruction.
As the popularity of polarized lenses increased, so did the availability of different lens designs and materials, such as single vision plastic, polycarbonate, Trivex, high index, flat top bifocals, lined trifocals, and progressives.
Essilor's Varilux is a well known brand among consumers. The company offers polarized lenses available in the Comfort, Panamic, Ellipse, and Ellipse 360.
The most effective way to sell polarized lenses is to demonstrate them to patients. Many manufacturer's of polarized lenses offer in-office demonstrations that allow the patient to view an image with and without polarized lenses. Having samples of colored polarized lenses allows patients to experiment with the different hues and intensities.
Step outside the office so patients can experience polarized lenses under different lighting conditions that they may be more familiar with.
A quick and entertaining way to demonstrate polarized lens' ability to block out light is to have a patient hold two polarized lenses toward a light, turning one lens. The patient will be able to see the lens darken until all the light is blocked.
Don't forget the importance of sun wear for contact lens wearers. A pair of polarized plano sun lenses allows wearers to have more clarity, contrast, and comfort while driving and in other lighting situations.
Oakley and Rayban have become synonymous with sun wear, both in the plano and prescription arenas. Serengeti eyewear offers Polarmax polarized polycarbonate lenses, available in gray and their signature Drivers lens colors.
Due to the technology involved in manufacturing, polarized lenses cost more than traditional tinted lenses. Clip-on sun lenses are a good way to introduce a budget minded patient to the benefits of polarization.
A patient will be more inclined to purchase a pair of dedicated polarized sun wear once they experience the superior performance of polarized lenses, and see an optician who has their needs in mind.
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