French ophthalmologist remembered for his studies of physiological optics and his work involving a disorder known as strabismus.
With his student Hjalmar August Schiøtz (1850-1927), he constructed an early keratometer, also known as the “Javal Schiötz ophthalmometer”. This device is used to measure the curvature of the corneal surface of the eye, as well as to determine the extent and axis of astigmatism. Javal also made important contributions in regards to the study of eye tracking, and with his assistant Marius Hans Erik Tscherning (1854-1939), he researched astigmatism and conducted studies in the field of optics.
Javal described eye movements during reading in the late 19th century. He reported that eyes do not move continuously along a line 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 ?azarz 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 the poor.
He died on 20 January 1907, aged 67, in Paris.

Link to Wikipedia biography