magnification in fine work, as reading stones, or to start fires. Olaf Schmidt has speculated that they may have been used as part of a telescope. See also Nimrud lens References External links Jewellery as Form of Personal Expression (includes picture of a silver mounted lens) Die Visby-Linsen (German, includes pictures of all the lenses found at Visby) Institut für Augenoptik Aalen, Projekte & Aktivitäten, Visby Linsen (German) Der Zeit voraus: Asphärische Linsen aus dem 11. Jahrhundert; Bernd Lingelbach, Olaf Schmidt; Das Fröjel Discovery Programme (German, extensive paper with many illustrations) Link to summary of all of 1999 excavation reports at Visby Germanic archaeological artifacts Viking art Lenses