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Sunglasses: Protecting Shields

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Have you set for a joyful vacation this summer? Do not forget to pack your sunglasses. Need a new pair? Bewildered by the huge array of choices and cannot decide? Let me offer some facts and helpful tips.
 
Sunglasses are meant to modify sunlight and match it to your eyes. They protect the eyes from Ultraviolet (UV) rays, intense light and glare, and eliminate uncomfortable direct or reflected light. Manufacturers use different technologies to provide ultimate protection to the eyes.
  • Tinting: Each of the tint colors perform a different job, as it is what determines the parts of the light spectrum that the lens absorbs. Grey tints, however, are the best for the general user; they reduce the overall amount of brightness with the least amount of color distortion and offer good protection against glare.
 
  • Photochromic lenses: These lenses use chemical reactions to protect against UV radiation. Millions of specific molecules that are transparent to visible light are imbedded in them; when exposed to UV rays, the molecules change their structure to absorb light, causing the lens to darken. The process occurs very rapidly in either direction.
  • Mirroring: Mirrored lenses have a reflective coating that is applied on a very thin layer. There are reflective molecules spread all over this layer, but covering only half of it; as such, the lens reflects half the light that strikes its surface, letting only the other half pass straight through. A major drawback is that the mirror coating can be easily scratched, because the scratch-resisting layer cannot be applied over it.
  • Scratch-resistant coating: These coatings are optically clear hard films applied to plastic lenses in particular. Through a process of ionization, an extremely durable fine film is created on the surface of the lens; this film is usually made of Diamond-Like Carbon (DLC) or polycrystalline diamond.
  • Anti-reflective coating: Similar to the scratch-resistant coating, it is a fine hard film layered on the lens. It prevents light hitting the back of the lenses from bouncing into the eyes, minimizing the glare you see.
  • UV coating: Make sure a statement on the label of your sunglasses says they filter out 100% of UV rays. This can save you the risk of many serious eye problems, including cataracts, macular degeneration, retina sunburns, and even blindness.

Be smart, there is a huge difference between lenses of cheap copied sunglasses and that of the genuine ones. Make sure you pay your money on a quality lens rather than a brand name; cheap sunglasses not only give the benefits up, but also harm your eyes. They might block some light causing the iris to widen, allowing more UV into the eye, which can damage both the cornea and the retina.
 
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