Term for the distance from the center of a lens to the pt. where parallel rays that pass through it converge
The point where they converge after passing through the lens is 
defined to ... Only when the object is a distance from the lens greater than the 
focal length... [DOC] [TLE] Lenses and Geometrical Optics - Optics For Kids - The Optical ... [PAR] The single point to which the light rays are converging is called the focal point.