“... this [invention] enables good sight and is one of the most useful of arts... the world possesses."
Fra Giordano da Rivalto, sermon (1305)
In the first century the Roman philosopher and dramatist Seneca used a glass sphere full of water resting on his reading material to magnify the letters, and this method was certainly used by farsighted monks a millennium later. Glass blowers in Venice produced lenses that were used as magnifying glasses, and in Europe in the late thirteenth century these were being used in pairs, one for each eye, the holding frame being made of wood or horn.
Salvino D’Armate of Pisa (1258-1312) and the friar Alessandro da Spina (d. 1313) of Florence are often given the credit for the invention of spectacles, in the year 1284, but Marco Polo, in 1270, saw elderly Chinese using spectacles and, when asked, they credited the
invention to Arabs in the eleventh century. The Chinese were also using smoky quartz as simple non- magnifying sunglasses at that time.
The first spectacles used convex lenses and corrected for presbyopia (farsightedness). In 1451 the German cardinal Nicholas of Cusa introduced spectacles with concave lenses that corrected for myopia (nearsightedness). The explanation as to why the lenses worked was given by Johannes Kepler in his 1604 treatise on optics. By around 1730 a London optician, Edward Scarlett, perfected spectacle arms that hook behind the ears, although it was some time before this became the preferred design.
