The Collaborative International Dictionary of English v.0.48:

Optography \Op*tog"ra*phy\, n. [Optic + -graphy.] (Physiol.)
   The production of an optogram on the retina by the
   photochemical action of light on the visual purple; the
   fixation of an image in the eye. The object so photographed
   shows white on a purple or red background. See Visual
   purple, under Visual.
   [1913 Webster]