The Visby lenses are a collection of lens-shaped manufactured objects made of rock crystal (quartz) found in several Viking graves on the island of Gotland, Sweden, and dating from the 11th or 12th century.
Some were in silver mounts with filigree, the mounting covering the back of the lens, and were probably used as jewellery; it has been suggested that the lenses themselves are much older than their mounts.[1]
Some of the lenses can be seen at the Fornsal historical museum in Visby, while some are in the Swedish National Museum in Stockholm, and others have been lost.
- ^ Schmidt, Olaf; Karl-Heinz Wilms; Bernd Lingelbach (September 1999). "The Visby Lenses". Optometry & Vision Science. 76 (9): 624–630. doi:10.1097/00006324-199909000-00019. PMID 10498003. Archived from the original on 27 February 2012.