Usuario:MissieSeal211
De Wikis en Educación
Contact Lenses are optical medical devices, just as spectacles are, and often provide cosmetic and optical advantages over them. The more than 35 million people in the United States who have opted for contact lenses over the use of glasses have done so because of their convenience, and cosmetic value. Many people initially feel discomfort when starting to use contact lenses, but the benefits of using them far outweigh these minor discomforts.
The Short History Of Spectacles
The invention of spectacles has greatly influenced progress in the arts and sciences, yet it is not very clear who invented this instrument. In 1270, Marco Polo saw elderly Chinese using this device, which they claim to have originated in Arabia in the 11th century.
The Spectacles Evolved in the western world from the late 1200s onwards, with riveted spectacles used by monks and scholars, who held the lenses in front of there eyes, or balanced them on their noses. The invention of the printing press in 1452 encouraged the mass production of spectacles, along with the growing popularity of books. For the lower and middle classes, there were spectacles mounted in wood, horn, bone, etc, whereas the upper classes used hand held spectacles in gold or silver frames.