Perspective

n.
  1. A glass through which objects are viewed.
  2. That which is seen through an opening; a view; a vista.
  3. The effect of distance upon the appearance of objects, by means of which the eye recognized them as being at a more or less measurable distance. Hence, aërial perspective, the assumed greater vagueness or uncertainty of outline in distant objects.
  4. The art and the science of so delineating objects that they shall seem to grow smaller as they recede from the eye; -- called also linear perspective.
  5. A drawing in linear perspective.
    6. Isometrical perspective ,
    an inaccurate term for a mechanical way of representing objects in the direction of the diagonal of a cube.
    Perspective glass ,
    a telescope which shows objects in the right position.