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The Relationship between Visual Acuity, Subjective Vision, and Willingness to Purchase Simultaneous-image Contact Lenses

Jong, Monica, PhD, BOptom1,2; Tilia, Daniel, MOptom, FAAO1,2; Sha, Jennifer, BSc, BOptom1; Diec, Jennie, BOptom1; Thomas, Varghese, MBioStat1; Bakaraju, Ravi C., BOptom, PhD, FAAO1,2*

doi: 10.1097/OPX.0000000000001359

SIGNIFICANCE This study reports that subjective vision ratings are better indicators of willingness to purchase simultaneous-image contact lenses than visual acuities and are more valuable in evaluating contact lens performance.

PURPOSE The purpose of this study was to investigate the relationship between visual acuities, subjective vision ratings, and willingness to purchase simultaneous-image contact lenses in presbyopes.

METHODS A retrospective analysis of visual acuities, subjective vision ratings, and willingness to purchase from final visits of two masked, crossover clinical trials of nine prototype and four commercially available simultaneous-image contact lenses in 141 presbyopes was performed. Pearson correlation and area under the receiver operating characteristic curve determined correlations between variables.

RESULTS Most subjective vision ratings were weakly correlated (r < 0.3) with visual acuity at all distances and illumination. Moderate correlations (r, 95% confidence intervals) were found between overall vision satisfaction ratings with visual acuity at 40 (−0.34, −0.28 to −0.40) and 50 cm (−0.33, −0.27 to −0.39), near-vision ratings (daytime) with visual acuity at 40 (−0.48, −0.43 to −0.53) and 50 cm (−0.46; −0.41 to −0.51), and intermediate-vision ratings (daytime) with visual acuity at 40 (−0.39, −0.33 to −0.45) and 50 cm (−0.41, −0.35 to −0.46). Highest discrimination for willingness to purchase was with overall vision satisfaction (area under curve, 0.93) and vision stability (daytime; area under curve, 0.77). Ratings from 4 to 9 for vision satisfaction showed a linear increase in willingness to purchase: a 1-unit increase in vision satisfaction increased willingness to purchase by 20%. Ratings lower than 4 had 0% willingness to purchase. Other subjective ratings showed similar relationships, albeit only 10 to 15% increase in willingness to purchase per unit increase for ratings higher than 4.

CONCLUSIONS Subjective vision ratings are a better indicator of simultaneous-image contact lens performance than visual acuity. Overall vision satisfaction and vision stability are key predictors of willingness to purchase. Subjective vision ratings should be used to evaluate performance rather than visual acuity alone.

1Brien Holden Vision Institute, Sydney, New South Wales, Australia

2School of Optometry and Vision Sciences, Sydney, New South Wales, Australia


Supplemental Digital Content: The Appendix, available at, is the subjective vision questionnaire used in the two clinical trials.

Submitted: May 18, 2018

Accepted: December 26, 2018

Funding/Support: None.

Conflict of Interest Disclosure: This project was funded by the Brien Holden Vision Institute, which has proprietary interests in the intellectual property governing extended depth-of-focus contact lenses (patent application number WO2014059465 A1). Brien Holden Vision Institute also receives royalties from the sale of Alcon multifocal contact lenses. Extended depth-of-focus and Alcon multifocal lenses were used in obtaining data for this nonproduct comparison study. All authors are employed by the Brien Holden Vision Institute.

Study Registration Information: Both trials were registered on the Australian New Zealand Clinical Trials Registry (ACTRN12615000652572, ACTRN12614000011684) and the U.S. clinical trials registry (NCT02484586, NCT02214797).

Author Contributions and Acknowledgments: Conceptualization: DT, JD, RCB; Data Curation: JS, VT; Formal Analysis: MJ, VT; Investigation: MJ, DT; Methodology: VT, RCB; Project Administration: RCB; Validation: MJ; Visualization: MJ, RCB; Writing – Original Draft: MJ; Writing – Review & Editing: MJ, DT, JS, JD, VT, RCB.

The authors would like to thank the clinical team (Ms. E. Robertson and Ms. B. Ludlow, D. Kho, C. Bishop, A. Munro, S. Delaney, J. Chung, J. Ozkan) and the database management team (Dr. T. Naduvilath and Ms. K. Laarakkers) for their invaluable support to run this trial at the Clinical Research Trials Centre, Brien Holden Vision Institute, Sydney, Australia.

Supplemental Digital Content: Direct URL links are provided within the text.

© 2019 American Academy of Optometry