title: The measurement of the corneal ellipse for the contact lens practitioner.
abstract: A keratometric instrument is described which can be used to measure the p-value of the corneal ellipse. The performance of the instrument is compared with that of the Guillbert Routit topographical keratometer and the Wesley Jessen P. E. K. The application of the p-value to contact lens fitting is discussed.
authors.affiliation: Department of Optometry, Bradford University, West Yorkshire, UK.
authors.forename: W A
authors.initials: WA
authors.lastname: Douthwaite
authors.forename: M
authors.initials: M
authors.lastname: Sheridan
mesh_terms: D000293:Adolescent; D000328:Adult; D003261:Contact Lenses; D003315:Cornea / Q000473:pathology*; D005069:Evaluation Studies as Topic; D006801:Humans; D009907:Optometry / Q000295:instrumentation*