Louis Émile Javal of text, but make short rapid movements (saccades) intermingled with short stops (fixations). Javal's observations were characterised by a reliance on naked-eye observation of eye movement in the absence of technology. Javal's interest in strabismus was due to the disorder affecting his father and sister. Javal himself had heterochromia. At middle-age Javal developed glaucoma, and by 1900 was totally blind. He was a friend of Ludwik Łazarz Zamenhof (1859-1917), the inventor of Esperanto, and he stressed the importance of learning this language by the blind. In addition, he was involved in social reform issues that included education and circumstances surrounding
Ludwik Hirszfeld Ludwik Hirszfeld Ludwik Hirszfeld (5 August 1884 in Warsaw – 7 March 1954 in Wrocław) was a Polish microbiologist and serologist. He is considered a co-discoverer of the inheritance of ABO blood types. He was a cousin of Aleksander Rajchman, a Polish mathematician, and of Ludwik Rajchman, a Polish bacteriologist. After attending the Gymnasium in Łódź, Hirszfeld, born into a Jewish family and later a convert to Catholicism, decided to study medicine in Germany. In 1902 he entered the University of Würzburg and transferred in 1904 to Berlin, where he attended lectures in medicine and philosophy. Hirszfeld completed his doctoral