The medallion's obverse bears portrait of Helmholtz, facing right, squinting through an optical instrument. Around top right, HERMANN VON HELMHOLTZ; signed at lower left, DAUB
The reverse show optical diagram of object, lenses and observer's eye to left.
Hermann von Helmholtz (1821-1894) was a German physician and physicist who made significant contributions in several scientific fields.
In physiology and psychology, he is known for his mathematics of the eye, theories of vision, ideas on the visual perception of space, color vision research, and on the sensation of tone, perception of sound, and empiricism in the physiology of perception.
In physics, he is known for his theories on the conservation of energy, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics.
As a philosopher, he is known for his philosophy of science, ideas on the relation between the laws of perception and the laws of nature, the science of aesthetics, and ideas on the civilizing power of science.
The circular medallion measures 98mm in diameter and was cast in bronze. No mintage is reported.