Glasses are made of a set of tools supporting the lens, typically used to aid vision or to protect the eyes and also for style. Special glasses used to view three-dimensional images from two-dimensional display. Modern glasses usually have a base in the nose. Spectacles including pince-nez first, Monocle, and lorgnette. Formerly lenses made of glass, but today many are made from various kinds of plastic, including CR-39 or polycarbonate. These materials can reduce the danger of breaking glass and the weight of glass. Some types of plastic also has a more reliable optical properties of glass, such as forwarding a better visible light and ultraviolet light absorption is better.
While contact lenses are corrective lenses, cosmetics, or therapy which is usually placed on the cornea. Contact lenses usually have the same utility with conventional glasses or regular glasses, but is lighter and shapes invisible when worn. Many blue colored contact lenses to make them more visible when cleaned, stored or when being used. Contact lenses are sometimes intentionally made other colors to change the appearance of the wearer’s eyes. There are an estimated 125 million people in the world who use contact lenses (2% of men), including 28-38 million in the United States and 13 million in Japan.
The patients with visual impairment began turning choose contact lenses because it is more practical and lightweight. In addition, currently available disposable contact lens that can be used disposable. So that the contact lens care is difficult and takes a long time can be avoided. Disposable contacts price cheaper than regular contact lenses. Cheap disposable contact lenses can be easily obtained at the nearest optical or through online stores.