Horner was born in
Zurich. After receiving his medical degree from the
University of Zurich in 1854, he continued his studies in
Vienna, where he learned
ophthalmoscopy from
Eduard Jäger von Jaxtthal (1818–1884), and in
Berlin, where he served as an assistant to ophthalmologist
Albrecht von Graefe (1828–1870). It was during this time that Horner decided to become an ophthalmologist himself. He returned to Zurich in 1856, and later opened his own eye clinic named "Hottinghof". Horner became a full professor of ophthalmology in 1873. After his death in 1886, his position at the
University of Zurich was filled by
Otto Haab (1850–1931).
Horner's syndrome, a disorder of the
sympathetic nervous system, was named after him following his description of the condition in 1869. His name is also associated with "Horner's muscle", the
lacrimal portion of the
orbicularis oculi muscle that is sometimes referred to as the "tensor tarsi muscle". With
Alexios Trantas (1867–1960), the "Horner-Trantas spots" are named, being defined as small whitish-yellow chalky concretions of the
conjunctiva around the
corneal limbus He was the author of numerous articles on ophthalmic medicine, published in
Carl Wilhelm von Zehender's
Klinische Monatsblatt für Augenheilkunde. ==References==