Polarized glasses have been popular with anglers and boaters for many years. It is only recently that polarized glasses caught on as a popular trend, however. Polarized glasses can dramatically reduce reflective glare, making it easier to see fine details in bright sunlight. However, it is important to understand the truth behind some of the rather grandiose claims regarding polarized glasses. Discover the myths and truths about polarized glasses.
Myth: Polarized Glasses Fully Block Glare
The concepts of glare and polarization are complicated, as are the interactions between the two. Normal light moves on many planes. When light waves bounce off of a reflective surface, however, they become polarized.
Polarized light moves mostly along one plane. A polarized filter most effectively blocks light that is polarized at a 90-degree angle with respect to the axis of the filter. More light is reflected and therefore polarized horizontally rather than vertically. Therefore, polarized sunglasses are vertically polarized. This drastically reduces horizontal glare.
However, the interrelationships between types of glare, polarization of both the glare and the filter, and the angle of the sun mean that polarized sunglasses will not effectively block all glare at all times.
Polarized sunglasses do maintain the traditional features of sunglasses. While your polarized glasses may not perform their polarization duties perfectly at all times, they will cut the brightness of ambient light. Polarized glasses cut the intensity of light by at least half. As with normal sunglasses, you can choose the level of darkness that you would like.
Myth: Polarized Glasses Are Expensive So They Must Be Good
Actually, price is no guarantee of quality.
Many very expensive polarized sunglasses do not meet industry standards for UV protection. Likewise, many inexpensive sunglasses are polarized and meet or exceed industry standards. Be sure to read the UV protection label on any sunglasses you are considering to see if the glasses are in compliance.
UV protection blocks dangerous ultraviolet light from reaching your eyes. Both UV-A and UV-B rays are harmful to the eyes as well as skin. Polarization does not block UV rays. A separate material must be added to polarized glasses to absorb the harmful radiation.
You will also need to ensure that the glasses you are considering are truly polarized. Many sunglasses have a test tag that you can use. Look through the glasses at the test tag, and then rotate the lenses 90 degrees. You should notice a significant darkening effect. If there is no test tag, look through two pairs of polarized glasses while rotating one pair 90 degrees. You should see an obvious blocking of light. Of course, most glasses are as advertised; but when paying extra for a particularly feature, it is good to be sure.
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Myth: Polarized Glasses Help In Driving
This myth is basically true, depending on the angle of the sun. On bright, sunny days, the sun’s light reflects off the shiny metal of cars. Light also reflects off of the asphalt of many road surfaces. Polarized glasses can block some of the reflected light, reducing dangerous glare and making driving safer.
However, polarized sunglasses will have little effect when the sun is in certain positions in the sky.
Motorcycle riders should avoid polarized glasses. The polarized filter combined with the darkening effect can make it difficult to distinguish details of the road surface. An oil slick or other hazard is potentially dangerous and may go unnoticed by a motorcyclist wearing polarized sunglasses.
Myth: Polarized Sunglasses are Excellent for Snow Skiers
Polarized glasses have their pros and cons for skiers. The polarized filter can help to dramatically reduce snow glare, which is caused by the sun’s light reflecting off the bright snow. Snow glare can be almost blinding on bright days, and the polarized sunglasses can help a skier to see. However, the polarized filter combined with the darkening sunglasses effect can make it more difficult to distinguish details, particularly when looking down. As a snow skier must always concern himself with the details of the snow just ahead on his path, the polarization can actually be dangerous. A skier may be unable to distinguish patches of ice and small moguls.
Myth: Polarized Sunglasses Make it Difficult to See LCD displays
This myth is completely true. When the display is viewed from certain angles, it may actually disappear. This has to do with the nature of the liquid crystal display (LCD). The light is polarized in such a way that the polarized glasses can make it disappear entirely. Always remove your polarized glasses before using an ATM or other LCD display.
For this reason, pilots who rely on LCD instrumentation for safe flying should not wear polarized glasses.
Myth: Thicker Glasses Provide Better Polarization
Polarized sunglasses are popularly available in two thicknesses: .75 mm and 1.1 mm lenses. The thicker lenses provide greater impact resistance. However, the polarization filter on both sizes is the same. Choose impact resistance if you need it, but do not be misled about the quality of the glare reduction.
Myth: Polarized Glasses are Good for Those Who Suffer Light Sensitivity
Photochromic lenses, often called transitional lenses, are frequently prescribed for people who are sensitive to light. These lenses automatically adjust to changing light sources, darkening in bright light and lightening in low-light conditions without any effort by the wearer. Many of these lenses are polarized as well. Those who suffer from light sensitivity are often particularly sensitive to glare, which makes prescription-polarized glasses with photochromic lenses an excellent choice.
Myth: Polarized Glasses are Not Available to Those Who Need Bifocals
While true bifocals or trifocals are not available with polarized filters, there is another option. Bifocals and trifocals have recently been replaced with progressive lenses. Progressive lenses transition seamlessly through a range of magnifications. They achieve a more natural enhancement of vision than the older bifocals and trifocals, and are free of the telltale lines. Progressive lenses are available with a polarization option.
Myth: Polarized Sunglasses Allow Boaters to See Through Water
This is partially true.
Due to the nature of water’s reflection of light, polarized glasses can make it easier to see underwater objects. The polarizing filter is vertical, while most of the reflected light of the water’s surface is horizontally polarized. The polarized glasses, therefore, can dramatically reduce glare from the water.
Additionally, polarized glasses cut the reflected light from other objects such as rocks. The light below the water’s surface is polarized vertically, so the vertically polarized glasses make the water appear darker. However, the lack of reflected light makes the water seem more transparent. Of course, the angle of the sun affects the amount of light that is polarized, thus affecting the ability to see more clearly.
Polarized glasses are a widely popular option in today’s market. Polarized glasses are able to reduce glare and improve vision in bright conditions. However, like any other product, polarized glasses have their advantages and disadvantages. Take the time to become educated about the way polarized sunglasses work. By being an informed consumer, you will be able to decide whether polarized glasses are right for you.