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Glass to glasses. Cyril W Kett Optometry Museum and Archive. Glass occurs naturally It was not until 3500 BC that glass was manufactured by man 4500 years later glass was used to make lenses that were inserted in a frame to make spectacles. Glass to glasses.
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Glass to glasses Cyril W Kett Optometry Museum and Archive Glass occurs naturally It was not until 3500 BC that glass was manufactured by man 4500 years later glass was used to make lenses that were inserted in a frame to make spectacles
Glass to glasses Cyril W Kett Optometry Museum and Archive Glass occurs naturally when quartz is heated to high temperatures by volcanic action or lightning strikes to vitrify silica (SiO2) It was valued for making cutting tools and decorative beads Manufactured glass is made by heating sand. It was first made in either Mesopotamia or Egypt about 3500 BC when it was found that adding sodium carbonate (Na2CO3) reduced the temperature required for vitrification below that which could be achieved by wood furnaces
Reconstruction of the palace where the Nimrud lens was found Glass to glasses Cyril W Kett Optometry Museum and Archive The Nimrud lens is the oldest extant lens, nearly 3000 years old, unearthed in the Assyrian palace of Nimrud in what is now Iraq 750-710 BC, discovered 1853, 38 mm diameter, 23 mm thick, plano convex, rock crystal, rough ground, +9 D Held by the British Museum
They developed from the glass covers used to protect reliquaries from the 8th C Glass to glasses Cyril W Kett Optometry Museum and Archive Reading stones were used from 1000 AD With powers of 30 to 40 D they provided magnification but did not correct an out-of-focus presbyopic eye
Glass to glasses 13th C Cyril W Kett Optometry Museum and Archive The first eyeglasses were made in Italy about 1286 Dominican friar Giordano da Pisa said in a sermon in Santa Maria Novella in Florence on February 23 1306: "It is not yet twenty years since there was found the art of making eyeglasses, which make for good vision ... And it is so short a time that this new art, never before extant, was discovered ... I saw the one who first discovered and practiced it, and I talked to him.”
Glass to glasses 14th C Cyril W Kett Optometry Museum and Archive Did Salvino D’Amato degli Armati of Florence invent eyeglasses? Florentine historian Domenico Manni (1690-1788) relates that there was a tombstone in the now demolished church of St Maria Maggiore Here lies Salvino D’Amato degli Armati of Florence inventor of eyeglasses May God forgive his sin Anno Domini 1317
Glass to glasses 14th C Cyril W Kett Optometry Museum and Archive Eyeglasses were depicted for the first time in a painting by Tomaso da Modena painted in 1352 The painting is part of a fresco in the chapter house of the monastery of San Nicolo in Treviso, Italy
Glass to glasses Cyril W Kett Optometry Museum and Archive 14th C The oldest surviving eyeglasses date from the early 14th C They were found in the Wienhausen monastery, near Hanover, Germany in 1953
Read this book Glass to glasses 14th C Cyril W Kett Optometry Museum and Archive Early eyeglasses had lenses of poor optical quality The lenses had striae, air bubbles and were poorly surfaced with asphericity and astigmatism. Ronchi test of 14th C rivet glasses by Rolf Willach 2008
Glass to glasses 14th C Cyril W Kett Optometry Museum and Archive The techniques of making spectacle lenses of good optical quality evolved over several centuries The glass workers of Venice developed blown glass lenses about 1300 - vitreos ab ocularis ad legendum - “glasses for the eyes for reading” The spectacle makers of Nuremberg developed mould-grinding in the late 14th C Read this book It is more about spectacle lenses than telescopes
Glass to glasses Cyril W Kett Optometry Museum and Archive 15th C The Trig Lane rivet spectacles are the oldest found in the UK. They date from before 1440 They were found during excavations in Trig Lane London in 1974 Replica of the Trig Lane spectacles
Glass to glasses 15th C Cyril W Kett Optometry Museum and Archive The printing press and a method of quickly making movable type were invented by Johannes Gutenberg about 1440 This led to the mass production of books By 1500, printing presses in Europe had produced more than 20 million volumes. There was now a great deal to read and a new demand for eyeglasses
Glass to glasses Cyril W Kett Optometry Museum and Archive 17th C The Worshipful Company of Spectacle Makers of London was granted its Royal Charter by Charles I in 1629 Spectacle makers had been regulated by city ordinances and by guilds in Venice, Nuremberg and in Holland for 200 years previously The London based Company of Spectacle Makers would provide examinations and qualifications for sight-testing opticians 270 years later, in 1897 1629