Joseph Hasner

Joseph Hasner, Ritter von Artha (August 13, 1819 - 1892) was an Austrian ophthalmologist who was a native of Prague. He studied medicine at the University of Prague, and subsequently was an assistant at Johann Fischer's eye clinic in Prague, and later a lecturer and professor of ophthalmology. His brother, Leopold Hasner (1818-1891) was an influentual Austrian politician.

Joseph Hasner was a professor at the University of Prague from 1852 until 1884. He is remembered for the discovery of plica lacrimalis which is a fold of mucous membrane that guards the lower opening of the nasolacrimal duct. This membrane goes by several other names, including Hasner's valve and Hasner's fold. He also put forth the theory that myopia was caused by stretching of the eyeball, being due to pulling on the posterior pole by the optic nerve. Among his numerous publications is Klinische Vorträge über Augenheilkunde (Clinical Lectures on Ophthalmology), which is a collection of Hasner's lectures on eye diseases and ophthalmoscopy.