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
Comparison between Ido and Interlingua Comparison between Ido and Interlingua Ido and Interlingua are two constructed languages created in the 20th century. Both have had some measure of success, but Interlingua has enjoyed greater diffusion and acceptance by public and private institutions—it is taught in many high schools and universities, for example. Ido is what is called "schematic" (easier to learn for speakers of very different languages), whereas Interlingua is what is called "naturalistic" (easier to understand for speakers of related languages). While both languages have a majority of Latin/Romance words in their lexicons, Ido has a somewhat larger number of Germanic and Slavic words,