April 2010
Volume 51, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2010
Prediction of the Optical Performance of Multifocal Contact Lenses Using a Physical Model Eye
Author Affiliations & Notes
  • R. C. Bakaraju
    Institute for Eye Research and Vision CRC, Sydney, Australia
    School of Optometry and Vision Science, UNSW, Sydney, Australia
  • K. Ehrmann
    Institute for Eye Research and Vision CRC, Sydney, Australia
    School of Optometry and Vision Science, UNSW, Sydney, Australia
  • D. Falk
    Institute for Eye Research and Vision CRC, Sydney, Australia
  • E. Papas
    Institute for Eye Research and Vision CRC, Sydney, Australia
    School of Optometry and Vision Science, UNSW, Sydney, Australia
  • A. Ho
    Institute for Eye Research and Vision CRC, Sydney, Australia
    School of Optometry and Vision Science, UNSW, Sydney, Australia
  • Footnotes
    Commercial Relationships  R.C. Bakaraju, None; K. Ehrmann, None; D. Falk, None; E. Papas, None; A. Ho, None.
  • Footnotes
    Support  From the Institute for Eye Research, Sydney, AU; Australian Government CRC Scheme through Vision Cooperative Research Centre, Sydney, AU; and School of Optometry and Vision Sciences, UNSW, Sydney, AU.
Investigative Ophthalmology & Visual Science April 2010, Vol.51, 5753. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      R. C. Bakaraju, K. Ehrmann, D. Falk, E. Papas, A. Ho; Prediction of the Optical Performance of Multifocal Contact Lenses Using a Physical Model Eye. Invest. Ophthalmol. Vis. Sci. 2010;51(13):5753.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: : To evaluate the in vitro optical performance of multifocal contact lenses (MFCL) using a physical model eye (ME) and also investigate the effects of lens decentration.

Methods: : A physical ME with the facility to change refractive, accommodative states, and pupil sizes, permitting the ‘fitting’ and optical testing of contact lenses was constructed. The ME was configured to simulate the presbyopic state with an axial refractive error and then corrected with MFCLs (AirOptixTM, AcuvueTM, Focus ProgressivesTM, ProclearTM, and PureVisionTM) with high add (+2.50D). The performance of MFCL in conjunction with ME was tested using an optical bench set-up consisting of HeNe laser (632.8 nm), pinhole, microscope objective and a collimator. Single-pass points spread function (PSF) measures were obtained at 3, 4mm pupils and 3 accommodative states [0, 1.50 and 2.50D], using a photo-sensor (2.2µm pixel pitch) situated at the retinal plane. PSF’s were post-processed to yield radial modulation transfer function (rMTF). Through-focus Strehl ratio was evaluated in the image plane by moving the sensor back and forth by 0.75mm, in steps of 0.1mm. Full-width on-axis interval occurring at half-maximum of Strehl’s was considered as depth-of-focus (DoF). Centration of MFCL was monitored by an integrated tracking camera.

Results: : In comparison with the best achievable single vision correction, all MFCLs drew smaller areas under the rMTF, particularly for distant and intermediate target vergences and 4mm pupil. For near, AirOptixTM and PureVisionTM designs achieved better performance than others at low (5c/d) and mid (15c/d) spatial frequencies. Through-focus Strehl’s predicted DoF in the range of 0.4 to 0.8 mm (1.25 to 2.50D). The DoF measures were higher for center-near designs. Decentration of MFCLs reduced both overall performance and the cut-off spatial frequency, as expected.

Conclusions: : The physical ME could discriminate between the performances of different MFCLs. When validated against clinical results, these predictions may facilitate better understanding of the performance and pitfalls of certain designs and assist practitioners in proper lens selection.

Keywords: presbyopia • contact lens • accommodation 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×