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Updated: Jun 7, 2026
05:46
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
Inherent ocular spherical aberration and multifocal contact lens optical performance
Ravi C Bakaraju1, Klaus Ehrmann, Arthur Ho
1Brien Holden Vision Institute, Sydney, New South Wales, Australia. r.bakaraju@brienholdenvision.org
Summary
Spherical aberration (SA) significantly impacts multifocal contact lens performance in presbyopic eyes. Lens design and individual eye SA levels interact, affecting visual quality, especially with larger pupils.
Area of Science:
- Ophthalmic optics
- Visual science
- Contact lens technology
Background:
- Presbyopia correction often involves multifocal contact lenses.
- Individual differences in ocular aberrations, like spherical aberration (SA), can influence visual outcomes.
- Understanding these interactions is crucial for optimizing lens design.
Purpose of the Study:
- To investigate the role of inherent spherical aberration (SA) in presbyopic eyes.
- To assess its impact on optical performance when corrected with simultaneous vision multifocal contact lenses.
Main Methods:
- Modeled presbyopic eyes (45- and 55-year-olds) with varying levels of inherent SA.
- Corrected ametropic models using four multifocal contact lens designs (low-add for younger, high-add for older).
- Evaluated performance using visual Strehl ratio and area under through-focus modulation transfer function.
Main Results:
- Significant differences in higher-order aberrations and through-focus MTF were found across SA models.
- Visual Strehl ratios varied insignificantly.
- Performance depended on pupil size and accommodation, with distinct differences for pupils ~4mm and larger.
- A low-add multizone design showed relative independence from inherent SA.
Conclusions:
- Ocular SA and correcting lens aberrations significantly interact.
- This coupling is a key factor in multifocal contact lens functionality.
- Individual SA levels necessitate tailored multifocal lens approaches.
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