Glasses, also known as eyeglasses or spectacles, are devices worn in front of the eyes to correct refractive errors or to protect the eyes from light exposure. They are nowadays also worn for aesthetic or fashion reasons.
According to historic records, the first pair of glasses was manufactured in Egypt in the sixth century B.C. They are thought to have been made of polished crystal which was attached to the head of the wearer using a kind of fixture. Modern spectacles, as we know them today, were invented in Tuscany at the end of the 13th century by Giordano da Rivalto, a Dominican monk.
The following sections provide information relating to spectacles such as spectacle types, lens types and manufacturing processes.