magnifying glass

From Wiktionary

Noun[change]

Singular
magnifying glass

Plural
magnifying glasses

Magnifying glass
  1. (countable) A magnifying glass is a lens, usually set in a frame with a handle, used to make small things look larger.
    The printing was so small he needed a magnifying glass to read it.

Notes[change]

The lenses are now often made of plastic, but are still called magnifying glasses.