Franciscus Cornelis Donders (1818–1889)

Franciscus Cornelis Donders was educated at Duizel and Boxmeer before entering the Military Medical School and the medical faculty at Utrecht University in 1835. In 1840, he received his MD from Leiden and spent 2 years in practice at Vlissingen before returning to Utrecht, where he was appointed as an extraordinary professor to lecture on forensic medicine, anthropology, general biology and ophthalmology. Refraction by the eye is complex, since the ray of light passes through many changes of refractive index in its path, and Donders simplified the account of the process by establishing an equivalent refractive system: the reduced eye. When Donders opened an Eye Hospital in 1858, he devoted himself to clinical ophthalmology, making fundamental advances in providing spectacles to correct errors of refraction—which he separated from errors of accommodation. In 1862, Donders was promoted as an ordinary professor at Utrecht and he handed over the greater part of his practice to his pupil Hermann Snellen. From narrow specialisation, Donders was freed to return to the broader physiology; subatmospheric pressure in the pleura was for a while referred to as ‘Donders’ pressure’; he also devised a method of measuring the mental reaction time taken in making discrimination, rather than the simple reaction time in which no choice is involved. He was widely honoured, presiding at international congresses, and elected as a foreign member of the Royal Society. He died suddenly on 14 March 1889, but his work lives on.