Allvar Gullstrand (1862–1930) was a Swedish ophthalmologist and Nobel Prize laureate (1911), who worked out the mathematical basis of astigmatism, and used mathematical methods to solve a number of other complex problems in geometrical optics. Gullstrand presented his doctoral dissertation at the Karolinska Institutet in Stockholm, but spent the majority of his career at Uppsala University, becoming professor of ophthalmology there in 1894. From 1914 to 1927 he held a personal professorship in physical and physiological optics freed from all teaching duties.