Customized Z-Lens Wavefront Optimization for Off-Axis Distortion
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Solution Overview
Problem
Traditional ocular lens manufacturing methods fail to adequately correct vision aberrations, particularly higher-order aberrations, leading to distortion when looking off-center, known as 'swim', which affects image quality and user experience.
Innovation Solution
A method to determine a wavefront for a spectacle lens using a patient's measured wavefront, incorporating additional factors like vertex distance, SEG height, and pantoscopic tilt, through optimization techniques such as hill climbing and Gaussian Least Squares Fit, to produce a customized lens with optimal correction across the entire lens surface, including off-axis gaze angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional lens manufacturing methods are used, then manufacturing process is simple, but distortion occurs when looking off-center (swim effect)
Solution Approach 1:
The lens surface is divided into multiple zones (central zone, intermediate zone, peripheral zone) with different optimization priorities. The central zone optimizes for best refraction, while peripheral zones optimize for reduced distortion, allowing each region to be tailored to its specific functional requirements without compromising the entire lens design
Solution Approach 2:
Different regions of the lens are given different optical properties through wavefront optimization. The central region provides optimal refraction for straight-ahead vision, while off-axis regions are specifically optimized to minimize distortion for peripheral gaze, creating spatially varying optical quality throughout the lens
2Manufacturing precision
If conventional subjective refraction is used, then off-axis distortion is reduced, but higher-order aberrations are not adequately corrected
Solution Approach 1:
The patient's complete wavefront is measured in advance using wavefront sensing technology before lens fabrication. This pre-measurement captures both lower-order and higher-order aberrations, allowing the lens to be customized to correct all measured aberrations simultaneously rather than relying on conventional subjective refraction alone
3Manufacturing precision
If wavefront optimization is applied to central zone, then best refraction is achieved, but off-axis gaze distortion increases
Solution Approach 1:
The lens design incorporates dynamic optimization that considers multiple gaze angles and directions. Rather than optimizing for a single central viewing angle, the wavefront is optimized across a range of gaze angles, allowing the lens to adaptively provide optimal correction for both central and peripheral vision through the freeform surface geometry
Data Source
AI summary
Embodiments of the invention pertain to a method for producing a spectacle lens with optimal correction across the entire lens taking into account the patient's complete measured wavefront. Specific embodiments can also take into account one or more additional factors such as vertex distance, SEG height, pantoscopic tilt, and use conditions. The lens wavefront can be achieved by optimizing a corrected wavefront, where the corrected wavefront is the combined effect of the patient's measured wavefront and the lens wavefront. The optimization of the corrected wavefront can involve representing the measured wavefront and the lens wavefront on a grid. In an embodiment, the grid can lie in a plane. During the optimization, a subset of the grid can be used for the representation of the measured wavefront at a point on the grid so as to take into account the portions of the measured wavefront that contribute to the corrected wavefront at that point on the grid.