 In 1897, Hippel attained the title of "professor extraordinary" at Heidelberg, and in 1909 became a professor at the eye clinic in Halle.In 1914, he became a professor of ophthalmology in Göttingen.In 1904, Hippel described a rare disorder of the retina, and in 1911 discovered the anatomical basis of this disease, which he named "angiomatosis retinae".