A student of Cornelius Donders in Utrecht, Herman Snellen (1834-1908) received his medical degree in 1857 and thereafter worked at the Netherlands Ophthalmic Hospital until he was made professor at the University of Utrecht in 1877. From 1884 to 1903 he succeeded Donders as the director of the Netherlands Ophthalmic Hospital. Although Snellen improved and invented a number of surgical procedures, including those for entropion, ectropion, and trichiasis, today he is best known for the vision letter-chart tests that bear his name. His son, Herman Snellen Jr, also became a professor of ophthalmology at Utrecht.
Herman Snellen. Arch Ophthalmol. 2011;129(5):574. doi:10.1001/archophthalmol.2011.100