Pseudo-accommodative IOL with Combined Diffractive Patterns
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Solution Overview
Problem
Conventional trifocal ophthalmic lenses degrade far and/or near vision to provide intermediate vision, lacking effective accommodation for multiple focal distances.
Innovation Solution
Trifocal ophthalmic lenses with diffractive structures that direct light to three focal regions, combining bifocal and trifocal patterns to enhance near, intermediate, and far vision, with bifocal patterns providing primarily two foci and trifocal patterns providing three foci, and a base curve for refractive power, optimizing energy distribution for improved visual acuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional trifocal lenses provide intermediate vision, then intermediate focus is achieved, but far and/or near vision is degraded
Solution Approach 1:
The lens surface is segmented into multiple diffractive patterns, with each pattern responsible for specific focal points. The first diffractive pattern creates first and second focal points, while the second diffractive pattern creates a third focal point. This segmentation allows each pattern to be optimized for its specific function, preventing degradation of any single focal region while providing multiple foci.
Solution Approach 2:
Multiple diffractive patterns are merged on the same lens surface to achieve multiple foci simultaneously. The patterns are designed with different diffraction efficiencies and focal characteristics, and their combined effect produces three distinct focal regions without compromising the quality of any individual focus, thereby resolving the contradiction between providing intermediate vision and maintaining far/near vision quality.
2Adaptability or versatility
If a single trifocal diffractive pattern is used, then three foci are provided, but energy distribution is suboptimal and visual acuity is reduced
Solution Approach 1:
The diffractive structure is divided into separate patterns, each optimized for specific diffraction efficiency at particular wavelengths and focal points. This segmentation allows precise control over energy distribution to each focal region, improving visual acuity by ensuring adequate energy reaches each focus without the compromises inherent in a single trifocal pattern.
Solution Approach 2:
Different diffractive patterns are designed with varying parameters including groove depths, spacing, and diffraction efficiencies. These parameter changes enable optimization of energy distribution across multiple foci, with each pattern contributing differently to the overall energy allocation, thereby enhancing visual acuity while maintaining multi-focal capability.
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
The solution provides enhanced intermediate vision while maintaining and often exceeding near and far visual performance, offering pseudoaccommodation for three distance ranges with improved visual acuity and reduced spherical aberration.
Implementation Method 1
bifocal diffractive pattern provides near and far vision and a trifocal diffractive pattern provides near, far, and intermediate vision
Implementation Method 2
The base curve can be adapted to provide a refractive power corresponding to the far focus
Data Source
Figure 1A~3
Figure 2
Figure 4A~4B
AI summary
In one aspect, a trifocal ophthalmic lens is disclosed that includes an optic having a surface that comprises at least one trifocal diffractive pattern and at least one bifocal diffractive pattern such that the bifocal pattern provides near and far vision and the trifocal pattern generates near, far, and intermediate vision. For example, the trifocal pattern can provide near, far, and intermediate foci such that the near and far foci are substantially coincident, respectively, with a near and a far focus of the bifocal pattern. In this manner, the trifocal and bifocal patterns collectively provide near, intermediate, and far foci (or focal regions) corresponding, respectively, to the near, intermediate and far vision.