East Germany (1950 SG E24) The Science Academy: von Helmholtz.
West Germany (1971 SG B394) 150th birth anniversary of von Helmholtz.
West Germany (1994 SG2594) 100th death anniversary of von Helmholtz.

Hermann von Helmholtz (1821-1894) was born in Potsdam near Berlin. He studied medicine at the Kaiser-Wikhelm 
Institute and did his clinical training at Charite Hospital. He had a wide range of interest including physiology, 
physics and chemistry. He made many important discoveries and published widely on subjects such as nerve 
conduction, visual and auditory physiology and X-rays. His greatest contribution to ophthalmology  was the 
invention of the direct ophthalmoscope in 1851. For the first time, the retina of the livings can be visualized and
disease pathology studied.