A magnifying glass is a lens that is used to produce a magnified image of an object.
The magnification of a magnifying glass depends upon where it is placed between the user's eye and the object being viewed, and the total distance between them.
The earliest evidence of a magnifying device was a joke in Aristophanes's The Clouds from 424 BC, where magnifying lenses to start kindling were sold in a pharmacy, and Pliny the Elder's "lens", a glass globe filled with water, used to cauterize wounds. (Senecawrote that it could be used to read letters "no matter how small or dim"). Roger Bacondescribed the properties of a magnifying glass in 13th-century England. Eyeglasses were developed in 13th-century Italy.