Ferdinand Monoyer (9 May 1836 – 11 July 1912[1]) was a French ophthalmologist, known for introducing the dioptre in 1872.[2]
He invented the Monoyer chart, used to test visual acuity.[3] He inserted his name in the random letters of the chart. It appears when one reads vertically from bottom to top on each side.[4]
^Koki, G.; Bella, A.-L.; Ndocko, K.-E. Mbassi; Epée, E.; Mvogo, C. Ebana; Bella, A.-L.; Ndocko, K.-E. Mbassi; Eballé, A. Omgbwa (2013). "Complications oculaires, à l'exclusion de la rétinopathie diabétique, chez le jeune diabétique de type 1, au Cameroun". Médecine des Maladies Métaboliques. 7 (5): 473–476. doi:10.1016/s1957-2557(13)70546-7. ISSN1957-2557.