A common question we are asked at events is about glasses… yes, glasses were available in the 13C, 14C and 15C – they may not be spec-savers fashion, but thousands benefitted from lenses in frames… See the links below for more information

Medieval Eyeglasses: Wearable Technology of the Thirteenth Century

http://glassescrafter.com/information/history-of-eyeglasses.html
https://en.wikipedia.org/wiki/Glasses#History
http://www.antiquespectacles.com/history/ages/through_the_ages.htm