Search International and National Patent Collections

1. (WO2018197905) METHOD AND APPARATUS FOR MEASURING ADD POWER OF A CONTACT LENS

Pub. No.:    WO/2018/197905    International Application No.:    PCT/GB2018/051141
Publication Date: Fri Nov 02 00:59:59 CET 2018 International Filing Date: Sat Apr 28 01:59:59 CEST 2018
IPC: G02C 7/04
G02C 7/02
Applicants: COOPERVISION INTERNATIONAL HOLDING COMPANY, LP
Inventors: WANG, Daozhi
HORAN, Laura
Title: METHOD AND APPARATUS FOR MEASURING ADD POWER OF A CONTACT LENS
Abstract:
A contact lens has a central region and an annular region surrounding the central region, the central region having a first optical power and the annular region having a second optical power. In a method of measuring the add power, the wavefront aberration of the contact lens is measured; a polynomial is fitted to the measured wavefront aberration. Terms of the polynomial correspond to types of aberration comprising defocus and astigmatism and residual aberrations. The add power is calculated as a defocus corresponding to the residual aberrations.