In 1847 physician Franciscus Donders was appointed as extraordinary professor at the University of Utrecht in the Netherlands. Among other medical disciplines he taught ophthalmology. In a small laboratory he started to examine refractive errors and accommodation in patients [4]. During his visit to the Great Exhibition in London in 1851, Donders learned from the German ophthalmologist Albrecht von Graefe (1828–1870) about the ophthalmoscope, prior to the publication of Helmholtz [5].
