Aspheric Intraocular Lens with Multi-Zone Profiles
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Solution Overview
Problem
Many intraocular lenses (IOLs) lack pseudo-accommodative optical power, resulting in a decreased depth of field and compromised vision, especially at varying pupil sizes, as they do not effectively mimic the natural lens's ability to adjust focus for different distances.
Innovation Solution
The design of IOLs featuring a central region and multiple outer regions with distinct asphericity profiles, each defined by a specific equation, providing varying depths of focus for different pupil sizes, thereby enhancing pseudo-accommodation and maintaining desired optical power and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If aspheric surfaces are included to counteract corneal aberrations, then image contrast is increased, but depth of field decreases
Solution Approach 1:
The lens surface is segmented into multiple zones with different asphericity profiles. The anterior surface includes a central zone with first asphericity, an intermediate zone with second asphericity, and a peripheral zone with third asphericity. This segmentation allows different regions to contribute differently to aberration correction and depth of field extension, resolving the contradiction between image contrast and depth of field.
Solution Approach 2:
Different zones of the lens are assigned different local optical properties (asphericity profiles) optimized for their specific function. The central zone prioritizes aberration correction for high contrast, while intermediate and peripheral zones provide progressive asphericity changes that extend depth of field without compromising central image quality.
2Device complexity
If monofocal power is provided, then optical simplicity is maintained, but pseudo-accommodation is lost
Solution Approach 1:
The lens utilizes controlled variations in asphericity parameters across different zones to create pseudo-accommodation. By changing the asphericity profile (a geometric parameter) from the central to peripheral zones, the lens provides multiple focal points without requiring mechanical movement or complex multi-element designs, thus maintaining optical simplicity while gaining adaptability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design increases the depth of focus by up to three diopters, providing improved near vision while maintaining quality distance vision, by varying asphericity profiles across different regions of the lens.
Implementation Method 1
The anterior optical surface includes a central region surrounded by a first outer region and a second outer region. The central region extends radially outward from a center point of the body portion and has a first asphericity profile. The first outer region extends radially outward from the central region and has a second asphericity profile that is different than the first asphericity profile of the central region. Finally, the second outer region extends radially outward from the first outer region and has a third asphericity profile that is different than the second asphericity profile of the first outer region.
Data Source
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AI summary
Aspheric optical lenses (e.g., intraocular lenses and contact lenses) are provided. The intraocular lens includes a body portion defining an anterior optical surface and an opposing posterior optical surface. The anterior optical surface includes a central region surrounded by a first outer region and a second outer region. The central region has a first asphericity profile. The first outer region has a second asphericity profile that is different than the first asphericity profile of the central region. The second outer region has a third asphericity profile that is different than the second asphericity profile of the first outer region. The overall asphericity profile of the optical lens provides different depths of focus for different pupil sizes. The result is an optical lens that provides increased depth of focus or pseudo-accommodation while maintaining desired optical power and performance.