Magnifying glass

A sheet magnifier consists of many very narrow concentric ring-shaped lenses, such that the combination acts as a single lens but is much thinner.

[1] Archaeological findings from the 1980s in Crete's Idaean Cave unearthed rock crystal lenses dating back to the Archaic Greek period, showcasing exceptional optical quality.

These discoveries suggest that the use of lenses for magnification and possibly for starting fires was widespread in the Mediterranean and Middle East, indicating an advanced understanding of optics in antiquity.

[2] The earliest explicit written evidence of a magnifying device is a joke in Aristophanes's The Clouds[3] from 424 BC, where magnifying lenses to ignite tinder were sold in a pharmacy, and Pliny the Elder's "lens",[4] a glass globe filled with water, used to cauterize wounds.

[7] In the late 1500s, two Dutch spectacle makers Jacob Metius and Zacharias Janssen crafted the compound microscope by assembling several magnifying lenses in a tube.

[8] 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.

In actual use, an observer with "typical" eyes would obtain a magnifying power between 1 and 2, depending on where lens is held.

High power magnifiers are sometimes mounted in a cylindrical or conical holder with no handle, often designed to be worn on the head; this is called a loupe.

The magnifying glass (, or U+1F50D in Unicode: 🔍) is commonly used as a symbolic representation for the ability to search or zoom, especially in computer software and websites.