Perfect sight is a concept as compelling as its history. The Roman Philosopher, Lucius Annaeus Seneca (4 BC- 65 AD) wrote, "letters, however small and dim, are comparatively large and distinct when seen through a glass globe filled with water,” and he used this observation to “read all of the books of Rome” ("History of Eyeglasses and Sunglasses”). Seneca allegedly gave such glasses to the Roman Emperor, Nero (Lewis). While, at the time, the magnification may have been falsely attributed to the water, crystals in the shape of lenses have been discovered as early as 100 AD. Scholars still debate the origin and properties of the first lenses; however, they agree that the observed magnifying properties of crystals were used to enhance vision around 700 AD (Lewis). Their non-perforated centers and a plano-convex form help distinguish lenses from glass jewelry. While it is known that ancient people recognized the magnifying powers of crystal, it is surprising that there is a lack of written history. This leads some scholars to believe lenses were not used for any commercial purpose in ancient times ("History of Eyeglasses and Sunglasses”).
There are three different schools of thought in Optical Science, none of them usurping the others: Emission Theory, Intro-Mission Theory, and Geometrical Optics. All three of these mindsets were laid to rest after the fall of the Roman Empire; at this time, scientists continued to research different properties of light in conjunction with the magnifying properties of crystals (Lewis). It was in 1284 that Italian crystal workers developed “reading crystals.” Two years later, Friar Salvino D’armate of Pisa created wearable eyeglasses by setting two magnifying glasses into bone, metal, or leather that could be balanced on the bridge of one’s nose. The production of different types of lenses, magnifying glasses, and eyeglasses increased rapidly in the following centuries until they took the form of eyeglasses that are known today ("History of Eyeglasses and Sunglasses”).