Average paraxial power of a lens and visual acuity

Stephen B. Kaye*, Jamila Surti, James S. Wolffsohn

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

To provide a solution for average paraxial lens power (ApP) of a lens. Orthogonal and oblique sections through a lens of power [Formula: see text] were reduced to a paraxial representation of lens power followed by integration. Visual acuity was measured using lenses of different powers (cylinders of - 1.0 and - 2.0D) and axes, mean spherical equivalent (MSE) of S + C/2, ApP and a toric correction, with the order of correction randomised. A digital screen at 6 m was used on which a Landolt C with crowding bars was displayed for 0.3 s before vanishing. The general equation for a symmetrical lens of refractive index (n), radius of curvature R, in medium of refractive index n1, through orthogonal ([Formula: see text]) and oblique meridians ([Formula: see text]) as a function of the angle of incidence ([Formula: see text]) reduces for paraxial rays ([Formula: see text]) to [Formula: see text]. The average of this function is [Formula: see text] providing a solution of [Formula: see text] for ApP.For central (p = 0.04), but not peripheral (p = 0.17) viewing, correction with ApP was associated with better visual acuity than a MSE across all tested refractive errors (p = 0.04). These findings suggest that [Formula: see text] may be a more inclusive representation of the average paraxial power of a cylindrical lens than the MSE.

Original languageEnglish
Article number7118
Number of pages7
JournalScientific Reports
Volume13
Issue number1
Early online date2 May 2023
DOIs
Publication statusPublished - 2 May 2023

Bibliographical note

Copyright © The Author(s) 2023.
This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.

Keywords

  • Applied optics
  • Medical research
  • translational research

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