Rizal went to Paris and Germany in order to specialize in ophthalmology to cure his mother's eye ailment. In Paris, he worked as an assistant to a leading French ophthalmologist. He then went to Heidelberg, Germany where he worked at the University Eye Hospital and befriended Professor Ferdinand Blumentritt. Rizal was later welcomed in Berlin's scientific circles where he associated with famous scientists and furthered his studies, while also working as an assistant in an ophthalmology clinic.