 He remained in Heidelberg as an assistant to Hermann Jakob Knapp (1832-1911) at the Heidelberg eye clinic, afterwards studying physiology under Carl Ludwig (1816-1895) in Vienna.From 1867 until 1870 he was an assistant to ophthalmologist Albrecht von Graefe (1828-1870) in Berlin.In 1871 he became director of the university eye clinic in Göttingen, and from 1890 to 1910 was director of the eye clinic in Heidelberg.