Source: NOVA: "Galileo's Battle for the Heavens" This resource was adapted from NOVA: "Galileo's Battle for the Heavens." As early as the 1300s, eyeglasses made from convex, or outward-curving ...

Fixing the different problems requires different lenses. Magnifying things close up requires a convex lens. A convex lens bulges. To see things farther away requires a concave lens.

In 1608, Lippershey laid claim to a device that could magnify objects three times. His telescope had a concave eyepiece aligned with a convex objective lens.

The properties of concave and convex lenses were first described around the year 1000, although magnifiers in the form of lens-shaped crystals or glass may have been used much earlier.