Now as for where eyeglasses came from (or rather when), it seems, 'the strain on the eyes of the medieval reader was great and the rooms in which they tried to read were darkened to protect them from heat; in winter the rooms were naturally dark'.* and medieval scribes complained constantly (often in the margins of the books they were transcribing) about the horrible light and terrible cold in which they laboured six hours a day. One young scribe named Florencio, in the 13th c. sometime, wrote '...it is a painful desk...the light extinguishes from the eyes, the work bends the back, crushes the viscera and the ribs brings forth pain to the kidneys, wearies the whole body.' Bad ergonomics in other words, and the obvious remedy was the invention of reading glasses, or spectacles, which came not long after (although no one really seems to have an exact place and date about the invention).
By Feb. 23, 1306, from the pulpit of the Church of Santa Maria Novella in Florence, a friar by the name of Giordana da Rivalto of Pisa reminded his parishioners about the Goodness of the Invention of Eyeglasses just twenty years beforehand. The Guild of Venetian Crystal Workers were known to have been grinding lenses as early as 1301, though another candidate for the spectacular discovery would be the Englishman Roger Bacon, who was rumored to have adapted an early Arab microscope smuggled into England by an manuscript illuminator, since in 1268 Bacon wrote a treatise upon 'opticks' in which he details 'the Examination of Letters or small Objects through the Medium of a Crystal or glass, which, if Shap'd like the Lesser segment of a sphere (convex), by which one sees the Letters far better and larger." So geek chic was borne into the world.
* from the Books of the Middle Ages Royal Ontario Museum (1950), quoted p. 292 Alberto Manguel's History of Reading (1994).
1. Redi. Lettra sopra l'invenzione degli occhialidi dinazo (Florence, 1648)
2. Kipling, Rudyard. 'The Eyes of Allah", Debits and Credits (London, 1926)
3. Roger Bacon, Opus Maius (London, 1750) ed. S. Jebb.