The eponym Hess afterimage refers to the German ophthalmologist Carl von Hess (1863-1923). It is used to denote a "positive afterimage that appears third in a temporal sequence of " afterimages resulting from a brief light stimulus. Hess afterimages have the same relative brightness relations as the primary optical stimulus. The term is used in opposition to "Hering's afterimage (the first in the temporal sequence of afterimages), and " Purkinje afterimage (the second in this sequence). The Hess afterimage can also be classified as a "physiological illusion.
References
Brown, J.L. (1965). Afterimages.In: Vision and visual perception. Edited by Graham, C.H. New York, NY: John Wiley & Sons.
Dictionary of Hallucinations. J.D. Blom. 2010.