The ray transference of a reversed optical system

Abstract

The optical character of an optical system is changed if the system is reversed.  This is as true of eyes as it is of telescopes.  In vision light traverses the eye from cornea to retina; in ophthalmoscopy the practitioner views the retina via light traversing the eye in the reverse direction.  The purpose of this paper is to determine the relationship of the optical character of the reversed system to that of the system itself. The result is in terms of the ray transference of the system.  Since the ray transference gives a complete characterization of the first-order optics of a system the analysis is complete in this sense as well.  Explicit expressions are also presented for the effect of reversal on the six fundamental first-order optical properties of the system.