Progressive Lens Astigmatism Mode Selection by Prescription Power

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Solution Overview

Problem

Existing progressive addition lens designs do not account for selecting an appropriate mode of transmission astigmatism based on the wearer's prescription power, leading to inconsistent wearer satisfaction.

Innovation Solution

A method for designing progressive addition lenses that selects between AS-oriented and PW-oriented modes of transmission astigmatism based on the wearer's prescription power, ensuring optimal visual field and satisfaction by adjusting the amount of transmission astigmatism added to the near and intermediate portions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transmission astigmatism is added to the near portion and intermediate portion, then visual field clarity is improved, but wearer satisfaction becomes inconsistent due to lack of mode selection

Engineering Contradiction:
Improvevisual field clarityVSAvoidwearer satisfaction consistency
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by switching between two distinct modes (AS-oriented mode and PW-oriented mode) that differ in their transmission astigmatism distribution patterns. The AS-oriented mode distributes astigmatism to expand the clear visual field range, while the PW-oriented mode distributes it to widen the near portion horizontal width and reduce skew distortion. This parameter switching resolves the contradiction by allowing optimal parameter selection for different wearer needs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamics by making the transmission astigmatism distribution adaptive rather than fixed. The design system dynamically selects between AS-oriented and PW-oriented modes based on wearer characteristics or prescription parameters, enabling the lens to adapt its astigmatism distribution pattern to different users, thereby ensuring consistent wearer satisfaction across diverse populations.

Inventive Principle:
Principle #15Dynamics

2Area of stationary object

If AS-oriented mode is selected, then clear visual field range is expanded, but near portion horizontal width and skew distortion control are reduced

Engineering Contradiction:
Improveclear visual field rangeVSAvoidnear portion usability
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The patent makes the transmission astigmatism distribution dynamic by allowing switching between AS-oriented mode (which expands clear visual field range) and PW-oriented mode (which optimizes near portion horizontal width and reduces skew distortion). This dynamic selection enables the system to prioritize visual field clarity when needed while maintaining near portion usability when required, resolving the contradiction between these two competing objectives.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If PW-oriented mode is selected, then near portion horizontal width is increased and skew distortion is reduced, but clear visual field range is decreased

Engineering Contradiction:
Improvenear portion usabilityVSAvoidclear visual field range
Core Design Contradiction:
Ease of operationVSArea of stationary object

Solution Approach 1:

The patent resolves this contradiction by making the transmission astigmatism distribution dynamic through mode selection. When PW-oriented mode is selected, the system prioritizes near portion usability with increased horizontal width and reduced skew distortion. When AS-oriented mode is selected, it prioritizes clear visual field range. This dynamic adaptability allows the same lens design system to optimize for different objectives based on wearer needs.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If a single transmission astigmatism distribution pattern is used, then design complexity is reduced, but adaptability to different wearers is limited

Engineering Contradiction:
Improvedesign complexityVSAvoidwearer-specific optimization
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies segmentation by dividing the transmission astigmatism distribution into two distinct patterns (AS-oriented and PW-oriented modes). Rather than using a single complex adaptive algorithm, the design is segmented into discrete, manageable modes that can be selected based on wearer characteristics. This segmentation maintains relative design simplicity while significantly improving adaptability to different wearers.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses parameter changes by switching between two predefined transmission astigmatism distribution patterns with different characteristic parameters. The AS-oriented mode has parameters optimized for clear visual field expansion, while the PW-oriented mode has parameters optimized for near portion width and distortion control. This parameter-based approach provides wearer-specific optimization without requiring complex real-time adaptation mechanisms.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4036638B1Design method for a progressive lens and design system for a progressive lens
Publication Date: 2026.04.01 HOYA LENS THAILAND LTD
  • EP4036638B1 patent drawingFigure 1~2
  • EP4036638B1 patent drawingFigure 3~4
  • EP4036638B1 patent drawingFigure 5~6

AI summary

Provided are a method for designing a progressive addition lens and the related technology, the progressive addition lens including a near portion for viewing a near distance, a distance portion for viewing a distance farther than the near distance, and an intermediate portion provided between the near portion and the distance portion and having a progressive refraction function, in which transmission astigmatism is added to the near portion and the intermediate portion out of the distance portion, the near portion, and the intermediate portion, the method including a mode selection step of determining, according to a prescription power, whether to select an AS-oriented mode in which the amount of transmission astigmatism to be added is set such that the amount of horizontal refractive power is larger than the amount of vertical refractive power, or select a PW-oriented mode in which the amount of transmission astigmatism to be added is set such that the amount of vertical refractive power is larger than the amount of horizontal refractive power.