Aphakic Intraocular Lens Diffraction Grating
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Solution Overview
Problem
Conventional aphakic intraocular lenses with diffraction grating structures struggle to provide secure multi-focusing effects, especially due to issues with pupil shrinkage and lens eccentricity, which affect intermediate vision contrast and stability.
Innovation Solution
A manufacturing method for aphakic intraocular lenses involving a diffraction grating with reliefs extending concentrically on the lens surface, where overlapping reliefs with different first-order diffracted light focal distances and synchronized grating pitches are used to generate multiple foci, ensuring effective diffraction intensity across vision ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional diffraction grating structure is used with 0th order light for far vision and first order diffracted light for near vision, then bifocal vision is achieved, but intermediate vision contrast becomes too low and energy allocation to mid-section is difficult
Solution Approach 1:
The patent divides the diffraction grating into multiple independent relief patterns (first relief pattern and second relief pattern) with different grating pitches. Each relief pattern generates diffracted light at different focal distances, allowing independent optimization of each focal zone. This segmentation enables simultaneous improvement of far vision (0th order), near vision (first order from first pattern), and intermediate vision (first order from second pattern) without compromising any single vision range.
2Adaptability or versatility
If multiple areas with different reliefs are formed on the lens surface to generate more foci, then the number of foci increases, but the lens becomes sensitive to pupil shrinkage and eccentricity, reducing focal effect stability
Solution Approach 1:
The patent applies different relief patterns to different radial zones of the lens. The first relief pattern with first grating pitch is positioned in an inner radial area, while the second relief pattern with second grating pitch is positioned in an outer radial area. This local differentiation allows each zone to optimize for specific focal distances while maintaining overall system stability. The inner zone handles near vision and the outer zone handles intermediate vision, reducing sensitivity to pupil size variations and lens position eccentricity.
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 method ensures stable and improved vision across far, near, and intermediate ranges by optimizing diffraction intensity and reducing stray light, enhancing the optical properties and focal accuracy of the intraocular lens.
Implementation Method 1
an intraocular lens capable of generating multiple foci by adopting a diffraction lens described, for example, in Patent Document 1 and the like and making use of diffraction of light
Data Source
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AI summary
Provided is a novel method of manufacturing an aphakic intraocular lens (10) that is capable of ensuring every multi-focusing effect more securely, while reducing the impact of aperture changes and lens eccentricity. At least two reliefs (26, 28) whose first order diffracted lights give respective focal distances different from one another are set to overlap with each other in at least a part of an area in a radial direction of the lens (10), and with respect to every grating pitches of one relief (28) having a maximum grating pitch among the reliefs (26, 28) set up in overlap, grating pitches of another relief (26) are overlapped periodically in order to obtain a relief pattern (24), so that the resulting relief pattern (24) is formed on a lens surface (16).