A pair of sunglasses and ultraviolet rays protection

10 May 2018 03:53

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<p>Sun glasses are protective devices that prevent eyes damaging and discomfort by reducing bright light and UV rays (Partridge, Eric The New Partridge Dictionary of Slang and Unconventional English). In the early 20th century, they were also known as sun cheaters (American slang).</p>
<p>From 10 a.m. until 2 p.m. the sun is high and Ultraviolet light is the strongest The closer you are to the earth’s equator; the higher altitude, and the more reflective the surface, the stronger it is. UV rays pass through clouds, so don’t be fooled into thinking protective eyewear isn’t necessary when the sky is cloudy. Even though shaded areas reduce Ultraviolet exposure, your eyes can still be exposed to rays that bounce from buildings, roads and other surfaces.</p>
<p>When choosing sunglasses, better to invest in wraparound frames, they limit sunlight more effectively; protection of UVA and UVB rays should be 99 to 100%; gray or brown are the best for color recognition. It is important to understand, that UV protection and darkness are not the same. A pair of sunglasses are especially necessary for people with macular degeneration, cataracts, etc.</p>
<p>Shades should protect your eyes from potentially damaging UV rays as well as the glare of the sun. If UV light passes through the sunglasses, it causes more damage then eyes without sunglasses at all. Eyes behind glasses dilate and more UV light reach the retina, unprotected exposure to UV light can lead to serious eye problems. So when buying shades, look for the percentage marking of UV blocking. Most sun lenses will have a sticker or a tag as well showing that they filter out 99% or 100% of ultraviolet.</p>
<p>The United States Environmental Protection Agency (EPA) developed the UV Index, and to protect your eyes from harmful solar radiation, sunglasses should block up to 100 percent of UV rays. A pair of $5 sunglasses may filter out 100% UV rays just as well as a $200 dollar pair. Generally, more expensive lenses have higher quality and provide a sharper, clearer image with less distortion. The sun radiates Ultraviolet that arrives on Earth in wavelengths 320-400nm (UVA) and 290-320nm (UVB), both UVA and UVB can be dangerous to your eyes.</p>
<p>Polarized shades are coated with a special film that helps reduce glare. Having this chemical film on polarized shades, you are able to see more clearly. Polarized sunglasses have been popular for years with boaters and fishermen who need to reduce reflected glare from the water surrounding them.</p>

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