Aspherical Intraocular Lens Correcting Multiple Visual Defects
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Solution Overview
Problem
Current intraocular lenses (IOLs) often fail to adequately correct visual defects due to their design being based on averaged corneal shapes, which do not account for individual variations, leading to suboptimal optical performance and the need for multiple lenses to address different visual defects.
Innovation Solution
A method for modeling an IOL that can correct at least two different visual defects depending on its orientation within the eye, utilizing surface and interior shape modifications to compensate for specific corneal geometries and aberrations, allowing for a single lens to address multiple correction tasks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If IOL design is based on averaged corneal shapes, then manufacturing and application are simplified, but optical performance is degraded due to individual variations
Solution Approach 1:
The patent applies parameter changes by modifying the surface geometry parameters of the IOL to create aspherical surfaces with specific curvature profiles. The surface is defined by mathematical equations that control the radius of curvature as a function of distance from the optical axis, allowing customization of optical properties while maintaining manufacturability through precise molding techniques.
2Measurement precision
If multiple IOLs are used to address different visual defects, then correction accuracy is improved, but device complexity and inventory requirements increase
Solution Approach 1:
The patent implements universality by designing a single IOL model with aspherical surfaces that can correct multiple types of visual defects including spherical aberration, astigmatism, and presbyopia. The aspherical surface geometry provides aberration correction capabilities that enable one lens design to serve multiple correction functions, reducing the need for multiple specialized IOL types.
Solution Approach 2:
The patent applies dynamics through the gradient curvature design of the aspherical surface, where the radius of curvature varies continuously from the optical axis outward. This dynamic geometric profile allows the lens to provide different refractive powers at different zones, enabling multiple correction functions within a single static lens structure.
3Ease of manufacture
If conventional spherical IOL surfaces are used, then manufacturing is simpler, but optical performance is degraded by corneal spherical aberration
Solution Approach 1:
The patent applies spheroidality by replacing conventional spherical lens surfaces with aspherical surfaces. The aspherical surface is defined by mathematical equations that describe a surface where the radius of curvature varies with distance from the optical axis, creating a more complex geometric form that better matches the optical requirements for aberration correction while remaining manufacturable through precision molding.
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 approach reduces the number of IOLs required and increases their applicability by enabling specific and deliberate correction of multiple visual defects with a single lens, achieving improved optical performance and reduced sensitivity to surgical inaccuracies.
Implementation Method 1
The human cornea generally exhibits a positive spherical aberration, which is typically offset by a negative spherical aberration of the natural crystalline lens. If this positive spherical aberration of the cornea is not accounted for, it will adversely affect the focusing of light by the combined system of cornea and an implanted IOL.
Implementation Method 2
By aberrations in this context is meant wavefront aberrations. This is based on the understanding that a converging wavefront must be perfectly spherical to form an ideal point image, i.e. if a perfect image shall be formed on the retinal receptor layer of the eye, the wavefront having passed the optical surfaces of the eye, such as the cornea and a natural or artificial lens, must be perfectly spherical.
Data Source
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AI summary
The invention relates to a method for modelling an intraocular lens, wherein the shape of at least one surface of the intraocular lens and/or the interior of the intraocular lens with respect to their refraction effect are configured in such a way that with a first orientation within a human eye the intraocular lens at least partially corrects a first visual defect of said human eye and with a second orientation within a human eye the intraocular lens at least partially corrects a second visual defect of said human eye. Further the invention relates to an intraocular lens.