Te·non \tə-nōⁿ\ , Jacques René (1724–1816), French surgeon. Tenon was an army surgeon who later became a professor of surgery and specialized in ophthalmology. In 1806 in a work on the anatomy of the eye, he described the space between the eyeball and the fibrous capsule of the eye. He also described the fibrous capsule itself which covers the posterior two-thirds of the eyeball and serves as a synovial sac. The capsule and the space have been named Tenon's capsule and Tenon's space in his honor.