1) Magnifying glass part 
A converging lens. ... Synonym: plus lens. ... (05 Mar 2000) ... 
Type: Term Definitions: 1. a converging lens. Synonyms: plus lens
A simple lens which causes rays of light from a subject to converge and form an image. 
A convex lens has a positive focal length, i.e., the focus is real (behind the lens). It is usuallycalled magnifying glass, since it magnifies the objects. It can be used to project an image.
Simple lens, or lens shape within a compound lens, whose surfaces curve outward. Such a lens causes rays of light passing through it to converge. (see Compound lens)
Lens that is thicker in center than at edges.The diagram shows the cross-section through a convex lens (shown as grey) and the light rays traced in red. See also: Converging Lens, Lens.
Click images to enlargeLens that possesses at least one surface that curves outwards. It causes light to deviate inward, bringing the rays of light to a focus, and is thus called a converging lens. A convex lens is thicker at its centre than at its edges, and is used to correct long-sightedness (hypermetropism). The d...