Friday, March 4, 2011

Why Are Polarized Lenses Necessary If Ever Choosing Eye wear

By Johnson Smith

Ever thought about what exactly polarized sunglasses do for ones eyesight, and additionally should it be an issue that ought to be factored into your selection, when shopping for some of those nice looking shades? There is a whole lot of technology contained in the production and assembly of premium sunglasses.

Polarized Sunglasses filter rays of sun light targeted on a horizontal plane. The expression polar, if used in mechanical architecture or in various other technical fields, would mean two lines are perpendicular, 90 degree angles to each other, consequently the concept of "polar coordinates". If sunglasses are polarized there is micro crystals sandwiched within the material of the lens components which in turn rejects the horizontally reflected light rays.

Direct sunlight consist of light rays which will radiate in all directions. As soon as the rays arrive at a smooth, flat surface, for instance a body of water, sand, snow, a sheet of glass, or perhaps asphalt, almost all the rays are reflected. The more reflective the surface, the brighter they seem. This in turn generates an oftentimes hazardous intensity of light rays which in turn is referred to as glare.

Reflected light rays are partially polarized, meaning that the light rays are traveling in a more concentrated, better aligned, less random, and more horizontal pattern. And since our eyes are lined up horizontally instead of vertically, (and thank goodness they are) we get bombarded with sunlight.

Polarized sunglasses had been used for decades by fishermen and also boaters who need to eliminate the glare on the lake. Nevertheless, a great many others which hang out, out of doors have realized the use of polarization. Affinity for this sort of lens has increased considerably.

One way to find out if your cheap sunglasses are really polarized is to hold them near your eyes just as you normally wear them, find an object that is brightly reflecting the sun and look through the lenses. Then move them down, you should see much more glare than when looking through the lenses. Now turn the sunglasses 90 degrees where the temples are vertical and look through one lens, and then move it aside just like before. Notice that the glare is about equal, with or without the lens. So if you really have polarized lenses, you will not see the glare through the glasses when held in a horizontal position, and you will see it through the lens in a vertical position, because the lenses are horizontally polarized.

Apart from people who love water sports, other people who profit significantly through the use of polarized sunglasses are joggers, bicyclist, as well as golfers. Polarized sunglasses can help each one of these see better through the elimination of surface glare.

They can be used for driving, and in fact, reduce glare from the long, flat surface of the hood of the car and the road's surface. But be aware that some automobile windshields are already polarized, and this doubled effect can create some strange patterns in the window glass. Polarized sunglasses also could be worn indoors if someone happens to be ultra sensitive to light.

Even though polarized lenses greatly improve comfort and vision, you will find some circumstances where polarized sunglasses may not be the best choice. For example consider downhill skiing, where you would not want to block the light reflecting from solid ice patches, because the skiers need to recognize the hazards ahead.

Also, polarized lenses may lessen the visibility of the images from an LCD (Liquid Crystal Display) sometimes found on the dash panel of vehicles or in other places like the digital screens at a bank ATM.

With polarized sun glass lenses, you also may not be able to see your cell phone or GPS screen. Pilots have also reported problems when reading Liquid Crystal Displays on their instrument panels,which can be a major issue if it comes down to a split second decision based on the data displayed.

However, for most of our sporting and other outdoor activities, polarized sunglasses are more of a necessity than a luxury. And so with the many choices of polarized sunglasses available, combined with the features and styling of the frames, wearing sunglasses seems as natural as wearing shoes.


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