What's it about?
This paper gives a basic survey of specifying aspheric forms, their function, and their manufacturing and testing. It is written from the manufacturer’s perspective.
The Aspheric Lens
Aspheric lenses contain at least one optical surface of nonconstant curvature. The variability of curvature is the primary differentiator from a spherical lens. Aspheric lenses are solids of revolution, where a general equation describes the cross section to be revolved. This is illustrated in Figure 1 below. Lenses of this style are capable of higher aberration order correction than spherical lenses...