[Spectacles--over and out? Past and future use of spectacles]

Spectacles are the most important optical aid and one of the most significant of inventions. History shows that ground rock crystals have been used for thousands of years. In Europe, eyeglasses were used from 13th century AD. Because of the loss of the eye's accommodation due to ageing--presbyopia--most people need eyeglasses for reading after the age of 50. Despite the developments of modern technology, it is still impossible to replace all use of eyeglasses.