Complex sentence: From 1866 to 1870 he was an assistant to ophthalmologist Carl Ferdinand von Arlt (1812-1887), and he later became director of the ophthalmology department at the "Allgemeine Poliklinik" in Vienna (1872).
Split into simpler sentences: From 1866 to 1870 he was an assistant to ophthalmologist Carl Ferdinand von Arlt (1812-1887). Later on, he became director of the ophthalmology department at the "Allgemeine Poliklinik" in Vienna (1872).