Slide Show of Early Non Spectacle Vision Aids

Quite a number of Mediterranean-area museums and many Middle Eastern museums apparently have display cases containing some plano-convex and also biconvex lens-like objects made of rock crystal or glass. Rarely is information provided as to the origins, sources, uses, or dates for these objects. Most of them seem to be in the range of about 20-30 mm in diameter. Occasionally one encounters a larger one, but most are of modest size. Some of the larger lens-like objects may have been used as items of veneration for religious purposes (Christian symbols of purity). Some of these museum cabinets even have larger assemblies of such objects. They were evidently valued, cherished and then even handed down between generations. These non-spectacles lens-shaped objects are also seen in the Greek Islands, in Greece, in Egypt, Crete, on the Riviera, and in Turkey.

We will likely never know for certain if any of these could have been used to enhance vision? However in his The Crystal Sun Robert Temple argues that with the abundance of examples of microscopic text and carvings from ancient times, they had to have known about magnification. Temple gives his theory of water globes and asserts that the Assyrian Layard Lens in the British Museum is the oldest optical lens in existence. He also believes that there are over 450 ancient optical lenses that curators instead think of just as trinkets and other decorative items.

Mirrors also played a key role in refraction and magnification for an extended period of time before the invention of spectacles. The oldest known ground mirrors made of obsidian (volcanic glass) were located in the South Konya Plain, near to the ancient city of Çatal Hüyük, in ancient Anatolia in modern-day Turkey. They have been estimated to be about 8000 years old (J.M. Enoch. Optometry and Vision Science 83(10):775-781, 2006). The image quality achieved in these mirrors is noted to be quite remarkable. Examples can be seen in the Konya Museum and they also are on display in the Museum of Ancient Anatolian Civilizations in Ankara. The existence of mirrors in some artwork also seems to indicate awareness of magnifying properties (Ilardi 2007).

In addition, we can comment on glass phials with bowled bottoms as they were commonly used in domestic settings. The bottom would be filled with water and when held or suspended by a pair of metal tongues near a window or fire, the water would act as a lens, focusing light onto the area you wanted to illuminate or magnify (ideal for sewing or doing small crafts). We can consider these as 'viewing globes' also, using the basic principal that a bowl of water will magnify objects. Such vials are occasionally seen in 14th and 15th Century paintings, where they serve a number of purposes. The little domestic details would have made the painting seem very 'real' to those viewing it, allowing the audience make an immediate connection between their lives and that of the Holy Family. However, the vials are also used symbolically to imply clarity of vision. In the Middle Ages, rock crystal was used as a symbol of the Immaculate Conception (the Virgin Mary is the crystal and Jesus is the divine light) and rock crystal viewing stones appear in the Spanish altarpiece The Annunciation of Mary painted by Jaune Huguet. It's likely that these glass vials had a similar meaning, especially as they appear predominantly in images of the Annunciation.

Click to see a Slide Show of Antique Non-Optical Sunshades (against sun, wind and snow)

(Move your mouse over any of the pictures below to see a larger image.)


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