(art) A technique in which an illusion of depth is created by painting more distant objects with less clarity, and with a lighter tone

plural of linear perspective

An optical illusion in which an object appears of a different size or distance away than it actually is.

A kind of early telescope. / (historical) An instrument for viewing an enlarged image of engraved prints or maps http://www.monticello.org/site/research-and-collections/perspective-glass.

plural of perspective glass

plural of isometric perspective

(art) A form of geometric perspective in which parallel lines are represented as converging in order to give the illusion of depth and distance.

plural of two-point perspective

A graphical technique in which a three-dimensional object is represented in two dimensions, and in which parallel lines in two of its dimensions are shown to converge towards two vanishing points

(idiomatic) To compare something with a similar thing to give a clearer, more accurate idea.