title: Generalizing Long's inversion of the matrix form of Prentice's equation and the concept of generalized inverse dioptric power.
abstract: The concept of generalized inverse dioptric power is introduced. Its use is illustrated in solving Long's matrix generalization of Prentice's equation for the decentration required to produce a specified prismatic effect. The solution holds in all cases for which a solution exists, including for the pure cylinder, and the result gives all solutions when more than one exists.
authors.affiliation: Department of Optometry, Rand Afrikaans University, Johannesburg, South Africa.
authors.forename: W F
authors.initials: WF
authors.lastname: Harris
mesh_terms: D005139:Eyeglasses; D006801:Humans; D008433:Mathematics; D055095:Optics and Photonics