The invention was made by using a frame (that could be wood, bone, metal,wire, and even leather) to hold together the 2 lenses. Early eyeglasses did not have arms to go around your ears instead you had to hold them up to your eye or placed on your nose. ( cybulskie)  

Fun facts about Europe in the middle ages.

Europe was in medieval times in the 5th-15th century. During the times of Medieval Europe the black plague was commonly having outbreaks. (HADDOCK) Other inventions in medieval times were the mechanical clock, windmill, and water wheel. 

Why were they needed?

Medieval Europe needed a solution on eye sight problems. Peoples eyesight could be damaged by a variety of things including birth defects, injuries, poor living conditions, and old age.

Interesting websites for extra knowledge

Websites that you can find helpful and interesting knowledge about eyeglasses

https://www.medievalists.net/2016/03/medieval-eyeglasses-wearable-technology-of-the-thirteenth-century/ ( Medievalists offers many articles about Medieval times and this website gives an insight on what eyeglasses were made out of)

https://www.jstor.org/stable/3173638?seq=1 (this Is a helpful link that talks about eyeglasses and the history of them)

https://www.journals.uchicago.edu/doi/10.1086/345566 ( This website talks about Medieval Europe and the Black plague that killed thousands.)

https://www.jstor.org/stable/24269428?seq=1 ( this website talks about the acceptance of eyeglasses in the Muslim world and more facts about them.)