A magnifying glass (called a hand lens in laboratory contexts) is a convex lens which is used to produce a magnified image of an object. The lens is u Stock Photo -
Light Lens Lab 35mm f/2 Eight Element
Film Friday: Light Lens Lab shows off its new 35mm F2 collapsible lens for Leica M-mount and screw mount cameras: Digital Photography Review
Determining Focal Lengths of Concave and Convex Lenses – Elementary physics laboratory iii