Overview

Historical records indicate that around the time of Christ the ancient Assyrians first realized that glass spheres could be used as magnifying devices. Claudius Ptolemy, a second-century mathematician and astronomer in Alexandria, wrote a paper on the optical properties of lenses. He discussed how glass spheres filled with water could be used for magnification and refraction. However, despite this knowledge, glass lenses were not extensively used for over a millennium. Around 1300, spectacles were invented to improve vision. This innovation served as the springboard to strong interest and research into the properties of magnifying lenses. Several treatises were published in the sixteenth century as a result. Near the end of the sixteenth century, it was found that if certain lenses were joined together by a cylinder, they would become what is called either a Galilean telescope or a Galilean microscope...