In the modern eyewear market, there are numerous options of eyeglass frames and lenses. General types include plastic frames, plastic lenses, metal frames, and glass lenses and so on. In addition, all these basic types can then generate a lot more combinations. So eyeglass customers living in the modern society are really lucky. It is worth noting that all of these eyeglass categories are not directly associated with their functionality. According to the latter aspect, eyeglasses have types such as prescription glasses, sunglasses and protective goggles. Thanks to technologically improvement, neither functional glasses nor accessory eyeglasses are limited by certain lens or frame materials. In the long history of eyeglass progression, the application of plastics as lens and frame materials has been a significant event. Before this breakthrough, nearly all eyeglass lenses were composed of glass and most eyewear frames were limited to metal ones. The invention of plastic frame eyeglasses and plastic lens eyeglasses was really a valuable gift for eyeglass users. (more…)