To maximize efficiency of the normally lengthy and costly multizone lens design and testing process, it is advantageous to evaluate the potential efficacy of a design as thoroughly as possible prior to lens fabrication and on-eye testing. The current work describes an ex vivo approach of optical design testing.
The aim of this study was to describe a system capable of examining the optical characteristics of multizone bifocal and multifocal optics by subaperture stitching using liquid crystal technologies.
A liquid crystal spatial light modulator (SLM) was incorporated in each of two channels to generate complementary subapertures by amplitude modulation. Additional trial lenses and phase plates were placed in pupil conjugate planes of either channel to integrate the desired bifocal and multifocal optics once the two optical paths were recombined. A high-resolution Shack-Hartmann aberrometer was integrated to measure the optics of the dual-channel system. Power and wavefront error maps as well as point spread functions were measured and computed for each of three multizone multifocal designs.
High transmission modulation was achieved by introducing half-wavelength optical path differences to create two- and five-zone bifocal apertures. Dual-channel stitching revealed classic annular rings in the point spread functions generated from two-zone designs when the outer annular optic was defocused. However, low efficiency of the SLM prevented us from simultaneously measuring the eye + simulator aberrations, and the higher-order diffraction patterns generated by the cellular structure of the liquid crystal arrays limited the visual field to ±0.45 degrees.
The system successfully simulated bifocal and multifocal simultaneous lenses allowing for future evaluation of both objective and subjective evaluation of complex optical designs. However, low efficiency and diffraction phenomena of the SLM limit the utility of this technology for simulating multizone and multifocal optics.
1School of Ophthalmology & Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
2School of Optometry, Indiana University, Bloomington, Indiana
Corresponding Author: Pete S. Kollbaum Indiana University School of Optometry 800 E Atwater Ave Bloomington, IN 47405 e-mail: firstname.lastname@example.org
Submitted: November 30, 2016
Accepted: May 16, 2017
Funding/Support: This research was partially supported by the Natural Science Foundation of Zhejiang Province under grant LY14F050009 (to Y.L.) and the American Optometric Foundation Vistakon Research Grant (to P.S.K.).
Conflict of Interest Disclosure: None of the authors have reported a conflict of interest.
Author Contributions: Conceptualization: YL, PSK; Data curation: YL, RX, PSK; Formal analysis: YL, AB, RX, PSK; Investigation: YL, AB, PSK; Methodology: YL, AB, PSK; Software: YL; Validation: YL; Visualization: YL, PSK; Writing – original draft: YL; Writing – review & editing: YL, RX; Project administration: AB, PSK; Supervision: AB, PSK; Writing – review & editing: AB, PSK; Funding acquisition: PSK; Resources: PSK.