Progressive Addition Lens Design for Presbyopic Visual Comfort
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Solution Overview
Problem
Current ophthalmic progressive addition lenses for farsighted and presbyopic wearers do not adequately enhance visual comfort, as they often result in suboptimal acuity and astigmatism correction across different gaze directions.
Innovation Solution
A method for designing ophthalmic progressive addition lenses that calculates and optimizes mean refractive power, astigmatism, and acuity loss values across various gaze directions, using specific criteria such as AcuityCriterion1 ≥ 44 D 2 .deg, to ensure improved visual comfort by balancing refractive power, astigmatism, and acuity loss, with the goal of enhancing the wearer's visual experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional progressive addition lenses are designed with standard optical parameters, then manufacturing is simplified, but visual comfort and acuity are insufficient
Solution Approach 1:
The patent applies parameter changes by optimizing specific optical parameters including mean refractive power PPO(α, β), module of resulting astigmatism ASR(α, β), and acuity loss value ACU(α, β) across different gaze directions. The method establishes specific threshold values for these parameters to ensure improved visual comfort while maintaining manufacturability through systematic optimization rather than complete redesign
Solution Approach 2:
The patent replaces traditional mechanical lens design approaches with an optical performance-based optimization system. Instead of relying solely on conventional lens manufacturing specifications, the method uses calculated optical criteria (AcuityCriterion1 ≥ 44 D²·deg) to guide lens design, substituting mechanical simplicity with optical precision
2Manufacturing precision
If lens design optimizes acuity and astigmatism correction, then visual comfort improves, but design and manufacturing complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the lens performance evaluation into distinct functional zones based on gaze direction (α, β). The method separately optimizes mean refractive power, astigmatism module, and acuity loss for different viewing conditions, allowing precise control of optical parameters in specific regions while maintaining overall design manageability
Solution Approach 2:
The patent implements feedback through the establishment of measurable criteria (AcuityCriterion1, AcuityCriterion2) that provide quantitative feedback on lens performance. The optimization process uses calculated values of PPO, ASR, and ACU against predefined thresholds to iteratively improve lens design, enabling precise control of acuity and astigmatism correction
3Reliability
If multiple acuity criteria are applied to optimize lens performance, then visual comfort enhances, but design complexity increases
Solution Approach 1:
The patent applies universality by developing a multi-functional optimization framework that simultaneously addresses multiple performance requirements through a single integrated approach. The method evaluates and optimizes mean refractive power, astigmatism correction, and acuity loss across all gaze directions using unified criteria, allowing one design process to satisfy multiple visual comfort requirements rather than requiring separate optimization for each function
Data Source
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AI summary
An ophthalmic progressive addition lens for a farsighted and presbyopic wearer having a mean refractive power, PPO(α, β), a module of resulting astigmatism, ASR(α, β), an acuity loss value ACU(α, β), where said (α, β) functions are determined in as-worn conditions of the lens by the wearer, and a first acuity criterion, Acuity Criterion1 which fulfils following requirement: Acuity Criterion1 ≥ 44 D².deg, and where: Acuity Criterion1 is defined as a combination of PPO(α, β), ASR(α, β), ADDp, and ACU(α, β).