Ibn Sahl
The use of a convex lens to form an enlarged/magnified image was most likely described in Ptolemy's "Optics" (which survives only in a poor Arabic translation). Ptolemy's description of lenses was commented upon and improved by Ibn Sahl (10th century) and most notably by Alhazen ("Book of Optics", c. 1021). Latin translations of Ptolemy's "Optics" and of Alhazen became available in Europe in the 12th century, coinciding with the development of "reading stones".