Progressive Addition Lens Optimization for Visual Comfort

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Solution Overview

Problem

Current ophthalmic progressive addition lenses for emmetropic and presbyopic wearers do not adequately enhance visual comfort, as they fail to optimize refractive power distribution and astigmatism correction for varying gaze directions, leading to suboptimal acuity and comfort.

Innovation Solution

A method using computer means to calculate and optimize the mean refractive power, astigmatism, and acuity loss values for ophthalmic progressive addition lenses, ensuring specific acuity criteria are met to enhance visual comfort, involving the determination of meridian lines and fitting crosses based on wearer-specific conditions and gaze directions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional progressive addition lenses are used for emmetropic and presbyopic wearers, then the lens can provide basic refractive correction, but the visual comfort and acuity are suboptimal due to inadequate optimization of refractive power distribution and astigmatism correction

Engineering Contradiction:

Improvevisual comfortVSAvoidrefractive power distribution optimization

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by optimizing the refractive power distribution across different gaze directions. The method calculates and adjusts the mean refractive power PPO(α, β) and module of resulting astigmatism ASR(α, β) for each gaze direction (α, β), transforming the lens design from conventional fixed parameters to dynamically optimized parameters that adapt to wearer-specific visual requirements and gaze patterns.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by providing gaze-direction-specific optimization of refractive power and astigmatism correction. Different regions of the lens are optimized for specific gaze directions, with the meridian line ML(α, β) and fitting cross FC(αFC, βFC) defining localized optical zones that tailored correct refractive errors for each viewing direction, rather than using a uniform lens design.

Inventive Principle:

Principle #3Local quality

2Reliability

If the lens is optimized for specific gaze directions with customized refractive power and astigmatism correction, then visual comfort and acuity improve, but the complexity of calculating and optimizing the optical parameters increases

Engineering Contradiction:

ImproveacuityVSAvoidoptical parameter optimization process

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs feedback by using wearer-specific as-worn condition data to optimize the lens parameters. The method incorporates feedback from actual wearer measurements and gaze direction data to iteratively adjust and refine the refractive power distribution PPO(α, β) and astigmatism correction ASR(α, β), ensuring the optimized lens parameters accurately reflect the wearer's visual needs and improve acuity.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces complex manual optical design processes with computational methods. Instead of traditional mechanical trial-and-error lens design, the system uses computer-based calculations to determine the optimized refractive power distribution and astigmatism correction for each gaze direction, substituting mechanical design iterations with digital optimization algorithms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of operation

If conventional lens designs are used without gaze-direction-specific optimization, then the manufacturing and fitting process remains simple, but the acuity loss and visual discomfort increase

Engineering Contradiction:

Improvelens fitting simplicityVSAvoidacuity loss value

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-calculating and pre-optimizing the refractive power distribution PPO(α, β) and astigmatism correction ASR(α, β) for various gaze directions before the lens is manufactured. The meridian line ML(α, β) and fitting cross FC(αFC, βFC) are predetermined based on wearer-specific data, allowing the lens to be manufactured with already-optimized optical parameters that minimize acuity loss across different viewing angles.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3362847B1Method for providing an ophthalmic progressive addition lens for an emmetropic and presbyopic wearer

Publication Date: 2024.01.17 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)

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AI summary

An ophthalmic progressive addition lens for an emmetropic and presbyopic wearer; method for providing such a lens. An ophthalmic progressive addition lens for an emmetropic 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 ≥ 435 D².deg², and where: Acuity Criterion1 is defined as a combination of PPO(α, β), ASR(α, β), ADDp, and ACU (α, β).