Vision Aids prior to the invention of Eyeglasses
There is a wealth of physical and documentary evidence supporting the availability of lenses for magnification in ancient times: The earliest documentary proof comes from Aristophanes (c 450-c. 385 B.C.) who mentions the use of plano-convex lenses and globes filled with water for magnification in his comedy play 'The Clouds'. Among the earliest of examples, the ancient Egyptians had lenses: the Louvre and the Cairo museums contain statues of pharaohs dating back 4600 years whose eyes are made from convex and concave lenses made from very high quality rock crystal.
Some of the manifold examples from early Roman culture may be viewed at first hand in the British Museum or the Louvre: These artefacts clearly demonstrate that artisan glass makers working in Rome in the first century AD produced both convex and concave lenses and mirrors. Moreover, they even developed a type of glass so clear as to resemble rock crystal - a feat the Venetians only emulated in 1300. Documentary evidence from the period supports the hypothesis that such glass must have been widespread in early Roman times. Pliny the Elder (23 - 79 A.D.) described the widespread use of glass and crystal in Roman society as a crazy addiction:
'there was one woman, who was by no means rich, who paid 150,000 sesterces for a single (rock crystal) dipper' [Pliny, Natural History, Vol X].
In 1868 Heinrich Schliemann excavated lenses from the site of the ancient Greek City of Troy which may date from between the 12 - 14th century B.C.
Recent excavations at a Viking site at Gotland Island yielded ten aspherical rock crystal lenses now known as the Visby Lenses. These appear to have been fashioned on a lathe in the eleventh or twelfth centuries and most probably originated in the Byzantine Empire. A treasure trove veritable wonder from the ancient world: while approaching the optical quality of modern lenses, they were made to the exact optimal shape for magnifying lenses a full 500 years before Descartes would calculate the exact specification for this shape - a fact which becomes all the more impressive when one considers that Descartes calculations were made at a time when the available technology could not produce such lenses. It must be therefore reasonable to presume that and some of the lenses made in antiquity must certainly have found application as visual aids for suffers of presbyopia.
Is it possible that glasses have been the most important invention of the last millennium? They might well be because they have effectively doubled the working life of all who need their eyesight to do fine work. It is an irrefutable point that many great achievements in art, academia, literature, science and technology were only made possible by the introduction of corrective spectacles to the world. It has been said that glasses have prevented the world from being ruled by people under forty. Yet, for all that, the true inventor of eyeglasses still remains obscure despite voluminous research and scholarly debate on the issue. Even after years of exhaustive research, the late academic and optical pioneer, Professor Vasco Ronchi summed the situation up well when he said 'the world has found lenses on its nose without knowing who to thank'.
Dr. Edward Rosen, fellow researcher of Ronchi, points to circumstantial evidence that the first pair of spectacles was invented around 1286 near Pisa in Italy. These early examples consisted of two glass convex discs enclosed in metal or bone rims with handles centrally connected by a tight rivet. In use they would either have clamped the nostrils or been held before the eyes. The evidence for this claim comes in the form of a scriptured Lenten sermon delivered and recorded at the Dominican Monastery of Santa Maria Novella in Florence in 1306 by the venerable Friar Giordano da Pisa:
'it is not yet twenty years since there was found the art of making eyeglasses, which make for good vision, one of the best arts and the most necessary the world has, And it is so short a time since this new art, never before extant, was discovered... and I saw the one who first discovered and practiced it and I talked to him'