Franciscus (Franz) Cornelius Donders FRS FRSE (27 May 1818 – 24 March 1889) was a Dutch ophthalmologist. During his career, he was a professor of physiology in Utrecht, and was internationally regarded as an authority on eye diseases, directing the Netherlands Hospital for Eye Patients. Along with Graefe and Helmholtz, he was one of the primary founders of scientific ophthalmology. Life He was born in Tilburg, the son of Jan Franz Donders and Agnes Elizabeth Hegh. He was educated at Duizel School and seminaries in both Tilburg and Boxmeer. By the age of seventeen, Franciscus Donders had started studying medicine in the School of Military in Utrecht. It was here that he discovered his passion for experimental study, specifically in the field of chemistry. By the age of twenty-two he entered the junior military in order to become a surgeon For several years, the young Donders studied at the Royal Dutch Hospital for Military Medicine in Utrecht, then earning his M.D. in 1840 from the University of Leiden. Following a stint as a medical officer in the Hague, in 1842 he was appointed as a lecturer in physiology and anatomy at the Utrecht military medical school. Because of his accomplishments in his studies, he made good connections that would allow for him to study his own scientific work. Soon after doing that he became a Professor for Anatomy and Physiology in 1847 at Utrecht University. In 1847, he became an associate professor at Utrecht University and, in 1862, attained a full professorship in physiology. In 1847, he became correspondent of the Royal Institute of the Netherlands, when that became the Royal Netherlands Academy of Arts and Sciences; in 1851, he joined as member. Donders knew that textbook knowledge had a lot to offer the field of cognition, but he also knew that it would be enhanced and hold more validity if experiments were involved. Donders was the first to discover that a lot of time is needed for an abstract mental process to occur. He is known for his work and research of eye disease and was among the first practitioners of the ophthalmoscope. He is credited with invention of an impression tonometer (1862), and for introduction of prismatic and cylindrical lenses for treatment of astigmatism (1860). Donders also was the first to use differences in human reaction time to infer differences in cognitive processing. He tested both simple reaction