It is a magnifying glass. A microscope is also used but is not technically hand-held and the majority of the time has more than one lens.
Magnifying glass
A magnifying glass is a hand-held instrument used to make an item look larger by magnifying its image when viewed through the lens.
Hand lens.
Hand lens
That sounds like a magnifying glass.
magnifying glass
A handheld device designed to make an item look larger is typically a magnifying glass. It consists of a convex lens that enlarges the appearance of objects when viewed through it. Magnifying glasses are commonly used for close-up tasks such as reading fine print, examining small details, or studying insects. They are portable and easy to use, making them a popular tool for both hobbyists and professionals.
spy glass
Binocular
A Microscope.
a magnifying glass?
No.