title: Approximate matrix expression for the thickness of any lens generalized to allow for prism.
abstract: A single approximate matrix expression is derived that gives the thickness at any point on any lens. The lens may have dioptric power or prism power or both. The expression gives, amongst other things, the equation for lines of constant thickness.
authors.affiliation: Department of Optometry, Rand Afrikaans University, Johannesburg, South Africa.
authors.forename: W F
authors.initials: WF
authors.lastname: Harris
authors.forename: H
authors.initials: H
authors.lastname: Abelman
mesh_terms: D007909:Lenses; D008433:Mathematics; D055095:Optics and Photonics