Visby Lenses Date Back 1,000 Years

(PCM) The Visby Lenses were found on the Swedish island province of Gotland

What:
Several lens-shaped pieces of quartz of varying size found in a Viking grave, dating back to the 10th century. Some are mounted in silver. Today, the lenses can be seen at Fornsal historical museum in Visby and the Swedish National Museum in Stockholm, both in Sweden.

Mystery:
The function of the lenses is unclear, and they possess technology highly sophisticated for …