Heinrich Müller

Heinrich Müller (17 December 1820 – 10 May 1864) was a German anatomist and professor at the University of Würzburg. He is best known for his work in comparative anatomy and his studies involving the eye.

He was a native of Castell, Lower Franconia. He was a student at several universities, being influenced by Ignaz Dollinger (1770–1841) in Munich, Friedrich Arnold (1803–1890) in Freiburg, Jakob Henle (1809–1895) in Heidelberg and Carl von Rokitansky (1804–1878) in Vienna. In 1847 he received his habilitation at Würzburg, where from 1858 he served as a full professor of topographical and comparative anatomy. As an instructor, he also taught classes in systematic anatomy, histology and microscopy.

In 1851 Müller noticed the red color in rod cells now known as rhodopsin or visual purple, which is a pigment that is present in the rods of the retina. However, Franz Christian Boll (1849–1879) is credited as the discoverer of rhodopsin because he was able to describe its "visual pigment cycle". Müller also described the fibers of neuroglia cells that make up the supporting framework of the retina. This structure was to become known as "Müller's fibers".

Alongside Carl Bergmann, Müller is credited as co-discover, in 1854, of the anatomical site where vision is initiated . Müller moved various lights over his own and other observers' pupils and scleras, producing moving shadows of the retinal blood vessels from motion parallax. This allowed him to reject the notion that conversion of light into vision happens closer to the light than the retinal blood vessels, as was accepted then. By careful measurement of the movements, he located the conversion of light into vision in the rods and cones.