glasseshistory.com

wL4KW TIL in 1887 contact lenses made of blown glass were invented, and were so heavy they could only be worn for a few hours.
GY4rj TIL that sunglasses were invented originally in 12th century China so that judges could conceal their eyes while interrogating witnesses.
v1abK TIL sunglasses made of smoky quartz were used in 12th century China not to protect from the sun’s rays, but to be used in courts to hide judges facial expressions