Custom Soft Contact Lens Design for Ocular Aberration Correction
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Solution Overview
Problem
Conventional contact lenses fail to effectively correct higher order ocular aberrations, particularly due to irregular corneal surfaces, which can lead to sub-optimal image focus and visual acuity issues, as they do not account for the unique topography of each individual's cornea and require costly and time-consuming fitting processes.
Innovation Solution
A method for designing a soft contact lens that utilizes corneal topography and wavefront aberration data to create a customized posterior and anterior surface, allowing the lens to conform to the cornea and correct both lower and higher order aberrations, eliminating the need for trial lenses and reducing fitting time by using a computer model to optimize the lens's optical zones and peripheral stability features.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional contact lenses are used to correct refractive errors, then defocus and astigmatism can be addressed, but higher order aberrations caused by irregular corneal surfaces cannot be effectively corrected
Solution Approach 1:
The contact lens design applies local quality by customizing the posterior surface curvature at different zones of the lens to match the unique corneal topography of each patient. The posterior surface is designed with varying curvature radii corresponding to different corneal regions, allowing precise compensation of higher order aberrations specific to each individual's corneal geometry.
Solution Approach 2:
The invention employs preliminary action by using computer-generated models to pre-calculate and design the optimal posterior surface configuration before manufacturing. The system models the corneal topography and wavefront aberrations in advance to determine the precise lens parameters, eliminating the need for trial lenses and reducing fitting time.
2Reliability
If trial lenses are used to fit contact lenses, then proper fitting can be achieved, but the process is costly and time-consuming
Solution Approach 1:
The invention uses a digital copy of the corneal topography and optical aberrations to design the contact lens parameters. By creating a virtual model of the eye's optical system and using wavefront aberrometry data, the system generates the optimal lens design without requiring physical trial lenses, thereby reducing fitting time while maintaining accuracy.
Solution Approach 2:
The system replaces the mechanical trial-and-error fitting process with a computational approach. Instead of physically trying multiple lenses, the invention uses computer algorithms to calculate the optimal posterior surface configuration based on corneal topography and wavefront data, significantly reducing fitting time and cost.
3Manufacturing precision
If the posterior surface of the contact lens is uniquely matched to corneal topography, then higher order aberrations can be corrected, but the lens design becomes more complex
Solution Approach 1:
The contact lens design segments the posterior surface into multiple zones with different curvature characteristics. Each zone corresponds to a specific corneal region and is designed with appropriate curvature to compensate for local aberrations. This segmentation allows complex aberration correction while maintaining manufacturability through standardized design parameters.
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 enables the production of contact lenses that improve visual acuity by accurately correcting ocular aberrations, reducing the need for trial lenses and associated costs, and simplifying the manufacturing process while ensuring rotational and translational stability, thus enhancing the fitting process and visual performance.
Implementation Method 1
light rays entering a refracting surface such as the cornea of the eye, or the lens
Data Source
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AI summary
Disclosed is a method of designing a soft contact lens, the method comprising the steps of: (a) measuring or defining a wavefront generated by passage of light through a selected eye and using the wavefront to generate a computer model of the optical characteristics of the selected eye; (b) measuring or defining the topography of the cornea of the selected eye; (c) incorporating into the computer model a soft contact lens, the posterior surface topography of which is defined by the topography of the cornea, offset by an arbitrary amount intended to represent the tear layer thickness of the selected eye, said lens having a defined thickness at a selected locus on the anterior surface; (d) calculating a desired topography for the anterior surface of the lens such that the wavefront will be corrected to assume a desired pattern (for example, preferably planar, the plane of which is perpendicular to the optical axis of the lens) when passing through the computer model eye/lens combination; (e) remodelling the lens off-eye by adapting the posterior topography of the lens to a desired posterior topography to be manufactured; and (f) recalculating a modified anterior topography required as a result of adapting the posterior topography, the modified anterior topography being intended to preserve the desired wavefront pattern defined in (d) when the lens is in situ on the selected eye.