In Templar’s Prophecy, the 4th book in the Lady Apollonia West Country Mysteries, set in 1397, I first wrote about the Lady importing lenses from Italy. The purpose was to aid her maid, Nan, in her embroidery as her eyesight was deteriorating as she aged. Some readers were not only surprised that such things were available in England at that time but even questioned the existence of eyeglasses that early.
Convex lenses are mentioned for enlargement and magnification purposes as early as the 11th century in Arabic texts. By the 13th century they were used in England while the Italians were experimenting with eyeglasses by then. There were guild regulations concerning the sale of eyeglasses by the beginning of the 14th century.
The detail of a portrait of the Dominican Cardinal and renowned biblical scholar Hugh of Saint-Cher, shown above, was painted by Tommaso da Modena in 1352. It shows the cardinal wearing something that looks much more like our eyeglasses of today than does a simple convex lens in a magnifying glass.
By the period in which my books are set, rivet spectacles were probably available. These were two magnifying glasses that were riveted together by the handles so they could grip the nose. An example of rivet spectacles, dating from around 1400, has been found in Germany. Therefore, I do not feel that I am stretching the truth by writing of their procurement in England by a wealthy noblewoman who could afford such things.
The picture above is in the Public Domain, https://commons.wikimedia.org/w/index.php?curid=4671939
For more information on the history of eyeglasses, click on
https://en.wikipedia.org/wiki/Glasses