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 Rajchman the first cousin of Ludwik Hirszfeld, a Polish microbiologist. Ludwik Rajchman is the father of Jan A. Rajchman, a Polish computer scientist, inventor of magnetic-core memory. Rajchman grew up in Warsaw in the difficult conditions of the Russian occupation. At an early age, he and his sister Helena became keenly aware of the social injustices in their "country" (Poland did not officially exist at the time) and were involved as teenagers in teaching young workers. As an adult, he joined the Polish socialist party (PPS) and was involved in the 1905 uprising and even arrested. After several months in prison