Eye-glasses: a stroll along centuries!
The origin of eyeglasses, such a stylish accessory nowadays, is quite mysterious.
The oldest known lens was found among the ruins of ancient Nineveh and was made of polished rock crystal.
Apparently no visual instruments existed at the time of the ancient Egyptians, Greeks or Romans. However, we can suppose that the Romans, great producers of glass, had used some devices to produce magnification. Around 50 A.D., the Roman philosopher Seneca noticed that objects appeared bigger if watched through a glass globe of water: however, he thought that the phenomenon was due to water rather than the glass curvature. Pliny the Older informs us that the emperor Nero used to watch gladiators fights using an emerald as spyglass because the colour green has a relaxing power on sight, as we all know today; but we cannot rule out the possibility that the stone he used had a particular cut that could correct myopia or other defects of vision.
In the eleventh century, the Arab polymath Alhazen observed that through a segment of glass sphere laid against reading material, it was possible to magnify letters. His work Opticae Thesaurus was translated into Latin by an unknown scholar at the end of the twelfth century or beginning of the thirteenth.It is probable that German and English monks were the first to put into practice his theories: they were using convex glasses, made of rock crystals, to read and copy their manuscripts.
Towards the end of 1200, the English philosopher Roger Bacon had the merit of guessing that convex lenses could be used to help people with problems of vision and make their reading easier. But he did not invent eye glasses, although he was without doubt contemporaneous to such an important invention.
The making of small discs of biconvex transparent glass in the glassworks of Murano goes back to the same period. And precisely during the making of these small objects, that were hung up on the windows of rich palaces, an anonymous artisan realised that thanks to them images appeared bigger and sharper.
The discovery of vision lenses were therefore absolutely fortuitous.
The most ancient documents expressly referring to the art of making magnifying lenses are the Venetian capitolari or statutes in 1300, in particular those of the artisans specialised in crystals.
In short… a genuine Italian invention!
The first known artistic representation of eye glasses was painted by Thomas from Modena in 1352: a man with glasses perched on his nose. The painting is preserved in the church of Saint Nicholas in Treviso.
Thence it arises that the first spectacles were made between 1268 and 1289, despite the name of the true inventor remains lost in obscurity.
Their use was for long time a prerogative of scribes, bookkeepers and notaries, in other words people who read a lot, so that they became a symbol of education, culture and nobility, also because the materials used for frames were very often gold, silver, horn and ebony, namely precious and expensive raw materials.
Only after the invention of printing, in the mid-fifteenth century, when large numbers of printed books began to appear, there was a significant development in the production of eye glasses all over Europe.
The first spectacles had biconvex lenses and were used exclusively to correct presbyopia.
The invention of bifocal lenses is commonly ascribed to Benjamin Franklin in the 1780’s, but it now seems that Franklin had only been one of the first people to use them. The original idea belonged to two distinct men who, in different places and dates, developed such a genial solution.
The different types of frames were created to solve an old problem: how to keep eye glasses on and make their use more and more comfortable up to the moment when modern bars were invented.
To conclude, a gestation of over 700 years to have eye glasses as they are today!