Carl von Hess (7 March 1863, in Mainz – 28 June 1923, in Possenhofen) was a German ophthalmologist known for his work in ocular physiology.
He studied medicine at the universities of Heidelberg, Bonn and Strasbourg, then traveled to Prague, where he worked with ophthalmologist Hubert Sattler and physiologist Ewald Hering.
In addition, he performed comparative physiological studies on light sense and color vision involving animals, in invertebrates as well as vertebrates.
Von Hess did discover that bees' phototactical response was colour-blind.
[4] He was also an editor of later editions of Saemisch and Graefe's "Handbuch der gesamten Augenheilkunde".