title: Thomas Young's contributions to geometrical optics.
abstract: In addition to his work on physical optics, Thomas Young (1773-1829) made several contributions to geometrical optics, most of which received little recognition in his time or since. We describe and assess some of these contributions: Young's construction (the basis for much of his geometric work), paraxial refraction equations, oblique astigmatism and field curvature, and gradient-index optics.
authors.affiliation: School of Optometry and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. d.atchison@qut.edu.au
authors.forename: David A
authors.initials: DA
authors.lastname: Atchison
authors.forename: W Neil
authors.initials: WN
authors.lastname: Charman
mesh_terms: D004739:England; D049671:History, 18th Century; D049672:History, 19th Century; D006801:Humans; D055095:Optics and Photonics / Q000266:history*; D009907:Optometry / Q000266:history*; D012030:Refractive Errors / Q000266:history* / Q000628:therapy