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How You Can Decide Whether You Should You Really Spend That Much on Sunglasses
by Gregg Hall Do you ever reach for your sunglasses before you move from your darkened house to the bright, clear day outside? Only on the day you have to purchase a new pair of shades do you think about exactly what you want perched atop your nose. You think about the technical and aesthetic differences. And then as you near the sunglasses store, you wonder if the $200 Serengeti pair really work better than the $10 pair you just tried on at the flea market.
Let us take the mystery out of sunglasses and help you look for what you want. We'll consider styles as well as what technology has done to improve lens composition. We'll also examine how light works and show you why light can actually make the sunglasses essential. The complexity and sophistication of a simple pair of dark glasses may well amaze you.
How do you pick your sunglasses?
Do you choose based on price, style, color, or name brand? The two pieces of tinted glass or plastic set in a plastic or metal frame might seem like a simple design at first, but scientists have found a way to manipulate these two pieces of glass or plastic to literally effect the user's eyesight once he slides them on. Differences between sunglasses really do exist.
What your sunglasses can do for you
Sunglasses should protect your eyes from ultraviolet rays in sunlight. Ultraviolet, or UV, light damages the cornea and retina. A great pair of sunglasses will eradicate the UV rays. Your glasses do not have to be ugly to provide great UV protection, most companies already include this as part of their glasses, even the inexpensive brands.
Sunglasses protect your eyes from intense light. Naturally a person's iris closes when the eye receives too much light. After the eye has closed the iris as far as possible, the eyelids will instinctively squint to prevent too much light from entering the eye. If squinting does not deter the light enough, like when sunlight reflects off the snow, the excess light will damage the retina. A great pair of sunglasses will block light entering the eyes as much as 97 percent and thus help the user avoid permanent retina damage.
Sunglasses protect eyes from glare. Reflective surfaces, like water, can reflect intense amounts of light, and bright spots will camouflage or hide objects. Good sunglasses will eliminate the glare with the use of polarization, which you can read about later in this article.
Sunglasses get rid of specific frequencies of light. Some frequencies of light will blur vision while others will enhance contrast. The right color of sunglasses will actually affect the frequencies and allow them to work better in a given situation.
The next time you consider buying a cheap pair of sunglasses, think about the entire purpose for them. You can actually damage your eyes with your tightwad tendencies. Sure, the cheap glasses will save you money, but in the end, you risk your eyesight. Gregg Hall is an author living in Navarre Florida. Find more about this as well as Designer Sunglasses at http://www.sunglassesandshades.com
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If You Participate In Any Outdoor Activities You Should Consider Polarized Sunglasses
by Gregg Hall When sunglasses were first invented they were not to help protect your eyes or even for their good looks. They were actually invented so a roman emperor could watch gladiators. Another early use of sunglasses was for interrogations in China over 500 years ago. Also, judges in China wanted to hide their facial expressions so they would wear shades so the witnesses could not see their reactions.
In the 18th century sunglasses saw a change. James Ayscough began experimenting with tinted lenses in spectacles. When Sam Foster introduced the shades to America in 1929, they became an instant hit.
Different from their predecessors, these glasses were designed to protect their wearer's eyes from the sun. Lens polarization soon followed thanks to Edwin Land who utilized his panted Polaroid filter to make sunglasses. Sunglasses sure came a long way from the Roman and Chinese roots.
So what is the Big Deal about Polarized Glasses?
Upon striking the water or any reflective surface, light becomes polarized. Nearly all of the light waves in polarized light move in one plane. Normal light waves move in many planes, while polarized lenses allow only light in one plane to pass through the lens. Thus polarized glasses nearly eliminate the glare.
Although sunlight is not polarized, water's surface reflects and transmits the separated components. The light literally breaks into the vertical and horizontal component, with the horizontal component reflected first. To nearly eliminate the glare, engineers designed a vertically polarized lens. The sun's height also affects polarization. Fishermen often wear polarized glasses with filters to help block the light reflected by the water's surface. Thus they can see under the surface of the water.
Can polarized glasses really work against the sun and get rid of all reflections?
No, these sun glasses eliminate parts of the reflective light and thus reduce the glare.
Should people who like to fish think about purchasing polarized glasses?
Reflective surfaces, like the water, reflect a great deal of light, and thus the bright spots can distract the fisherman or even hide objects, like the fish. Good sunglasses will eliminate the glare with polarization. Natural or artificial light can polarize. Anytime you look at a lake or river, you are seeing naturally polarized light. The reflected glare off the water is the light that doesn't make it through the "filter" of the water, and thus you cannot see anything below the surface, even when the water is clear.
Polarized light results from light striking the surface of the water horizontally. Fishermen wear polarized lenses that allow vertically polarized light to enter, and thus he can see into the water and spot fish and structure.
How do polarized sun glasses and normal sun glasses differ?
It is important to buy glasses that you feel comfortable with. You should not purchase polarized glasses just because they say they are better. But the truth is that normal sunglasses merely decrease the intensity of all light passing through their lenses. Polarized light also decreases light, but it does so selectively. Thus the polarized lenses selective eliminate the reflection from the light off the water's surface.
Polarized glasses are great for a variety of outdoor sports and projects. They are great in the winter, summer, fall, and spring. You really do not need to buy any other sun glasses if you own a pair of polarized sun glasses.
If you are interested in purchasing a pair of polarized sun glasses the Internet is a great source of information. You may even find a few good sites to make your purchase from. Gregg Hall is an author living in Navarre Florida. Find more about this as well as Designer Sun glasses at http://www.sunglassesandshades.com
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