Nowadays, the huge variety of eyeglasses in the store may differ in lens material, frame material as well as their styles. There are commonly referred metal eyeglasses and plastic glasses. In most cases, the term "plastic eyeglasses" refers to eyeglasses that have plastic frames. This is particularly true when some citizen want to compare metal spectacles with plastic ones. These two frame materials do have some different features. They both have their respective pros and cons. However, plastic eyeglasses can also be used to narrate glasses made of plastic lenses. When we compare plastic eyeglass lenses, they were undoubtedly a great invention in the 20th century, before which nearly all eyeglass lenses were made from glass. It is widely known that glass lenses are quite heavy that a pair of these lenses can exert primary weight on the wearer's nose. Worse still, glass lenses are quite brittle so that they will break easily. In a serious case, the eyes may get injured. It was these disadvantages of glass lenses that forced innovators to create an alternative.
[b]Lens[/b]Lightweight, shatter-resistant plastic lenses are the excellent solution. In general, plastic eyeglass lenses are much lighter, safer and more durable than glass lenses. These advantageous features are very important for many wearers. They can enjoy relieve and safety from these plastic eyeglasses. It is estimated that roughly 70% of the world's eyeglass lenses are made of plastic. After a concentrate of decades' progression, there are currently many forms of plastics that can be used to make eyeglass lenses. Most of these involved plastics have further advantages compared with traditional plastic.
As a special plastic, Cr-39 has been the approved material for eyeglass lenses for many years. Lenses made from this material have only a half the weight of glass lenses. In addition, Cr-39 eyeglass lenses have good Uv light protection. Being less likely to shatter, Cr-39 plastic eyeglasses can still be treated with advanced coatings such as scratch-resistant coating. Someone else special divergence of plastic is polycarbonate, which features climatic characteristic resistance, impact resistance and optical properties. Polycarbonate eyeglass lenses are thinner and lighter than Cr-39 lenses. An astonishing highlight of these lenses is that they are 10 times more impact-resistant than glass or regular plastic lenses. As a result, polycarbonate lenses are adored by safety glasses and children's eyeglasses. There are still high index plastic lenses, which are commonly thinner and lighter than regular Cr-39 plastic lenses. They undoubtedly refer to a variety of plastic lens materials.
Lens Materials of Plastic Eyeglasses
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