Some more Tiffany and Co Key Necklace Jewelry Outlet lenses including the following species:
1, glass lens
Glass lenses have characteristics of the lenses more scratch-resistant than other materials, but also relative to their weight Sunk its relatively high refractive index: 1.523 ordinary tablets, ultra-thin: 1.72 per cent, up to a maximum of 2.0.
2, polymer resin lenses
Polymer resin lens lighter than glass lenses, impact resistance is not easy to break, but because of its low hardness, scratch more easily than glass.
3, PC lens
There is also a material more impact-resistant than the polymer resin, often used in aeronautical equipment, transparent Windows, police on the mask, and an astronaut helmet mask, its only about glass one-tenth weight, compared with traditional plastic lenses are only half the weight.
General PC lenses require plus the anti-scraping after the protective film, will be enough to get better at the using time, mostly for children's eyeglasses, eye shields or athletes. PC lens also has an important feature, namely PC lenses with isolated from harmful UV effects, but its shortcomings are also easy to scratch the surface.
4, bifocal lenses
Bifocal lenses can also correct both far and near Visual acuity, mainly for the presbyopia correction needed. General distribution of bifocal lenses: the upper part of the lens to see from a distance, lower the lenses used to watch a little closer, Fan Wei's size, depending on the nature of the work used to order it.
Highest chances of generally flat-topped two-light is used, they only have a small area at the bottom of the lens to use as closer, lens around to upper to gaze far away and provide a good peripheral vision. Traditional of double light Cheap Oakleys Frogskins Sunglasses Outlet lenses for line double light of lenses, lenses by middle is divided into upper and lower two Department copies, is lenses of half following all as near points distance by with, they provides comparison good of wide of near points vision, for more long time Yu near points workers has more better of effect, architects, accountants, artist and other work nature phase near who, this species lenses can reduced head swing of opportunities. Bifocal lenses can also be used; people who only read the correction needed to close, but a little closer to work but could not place the glasses down.
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5, three focus lenses
For people who need to distance vision (usually about 18 inches to six feet), far and near, three-focus lens can be used to meet such needs, people who work in front of the computer or cash register, this distance vision particularly in demand, such lenses can meet the vision requirements of his work.
These lenses of correction effect is contains multiple range, different of is in each a different distance of Discount Oakleys Flak Jacket Sunglasses Cheap lenses its line not obviously, these more focus lenses of line, may needs in is near of Department, only can see get or through hand of touch only can feels to, but, dang using who in conversion by near to distance Shi, eyes still will has feels to is big of suddenly changes.