Matching of subjective and objective refractions

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Solution Overview

Problem

Existing methods for determining refractive errors in spectacle lenses, such as subjective and objective refraction, suffer from inaccuracies and deviations, making it difficult to determine suitable target values for correcting the wearer's refractive error accurately.

Innovation Solution

A series of spectacle lenses with associated specifications, each characterized by measurements from different types of devices, accounting for measurement inaccuracies and deviations, and a method to calculate an estimated refractive error by combining these measurements to minimize systematic and statistical deviations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If objective refraction determination is used, then measurement speed and objectivity are improved, but measurement precision deteriorates due to systematic deviations from subjective refraction values

Engineering Contradiction:
Improvemeasurement speedVSAvoidrefraction measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent combines objective refraction determination (automated, fast) with subjective refraction determination (accurate, slow) into a unified measurement process. The system integrates both measurement types and their respective reference value sets to compensate for the systematic deviations that plague each method when used alone, thereby achieving both speed and precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the parameters by introducing multiple reference value sets corresponding to different measurement types and conditions. By selecting and weighting appropriate reference values based on the specific measurement context, the system adapts to minimize systematic deviations while maintaining measurement speed.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If subjective refraction determination is used, then measurement precision is improved through expert assessment, but device complexity and time consumption increase

Engineering Contradiction:
Improverefraction measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a computer-based evaluation unit as an intermediary that processes both objective and subjective measurement data. This intermediary automatically compares measured values against multiple reference value sets, determines deviations, and calculates corrected target values, thereby reducing the complexity burden on the human expert while preserving measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces part of the manual subjective assessment process with automated computational analysis. The system uses algorithms to evaluate measurement deviations and determine corrected target values, substituting mechanical human judgment with electronic processing to reduce overall system complexity while maintaining or improving precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If multiple measurement types are combined, then measurement precision is improved by compensating for systematic deviations, but device complexity and calculation complexity increase

Engineering Contradiction:
Improverefraction measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the measurement system into distinct modules: an objective measurement unit, a subjective measurement unit, and a separate evaluation unit. Each module handles specific tasks independently, and the evaluation unit systematically processes data from both measurement types against multiple reference value sets. This segmentation manages complexity by organizing the combined measurement process into manageable, independent components.

Inventive Principle:
Principle #1Segmentation

4Reliability

If reference values from different measurement types are used, then reliability of target values is improved, but loss of information increases due to different measurement scales and components

Engineering Contradiction:
Improvetarget value reliabilityVSAvoidmeasurement data compatibility
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent transforms the reference value data by introducing deviation metrics that quantify differences between measured values and reference values across different measurement types. The system calculates these deviations systematically and uses them to weight and integrate reference values appropriately, thereby maintaining information integrity while improving target value reliability through multi-source validation.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3926390B1Matching of subjective and objective refractions
Publication Date: 2025.10.08 RODENSTOCK GMBH
  • EP3926390B1 patent drawingFigure 1A~1B
  • EP3926390B1 patent drawingFigure 1C
  • EP3926390B1 patent drawingFigure 2A~2B

AI summary

The present invention relates to a spectacle lens for correcting the refractive error of a wearer's eye and to a series of spectacle lenses. The spectacle lens has a first effect P_A at a reference point of the spectacle lens, wherein: the refractive error is characterized by at least a first measured value P_A1, obtained by means of a measuring device of the first type for measuring the refractive error and consisting of several components, and at least a second measured value P_A2, obtained by means of a measuring device of the second type for measuring the refractive error and consisting of several components, wherein the first measured value P_A1 and the second measured value P_A2 differ in at least one component X;The component X of the first effect P_A present at the reference point of the spectacle lens is closer to the component X of the measured value among the measured values ​​P_A1 or P_A2 of the spectacle lens which is obtained by the measuring device with the lower inaccuracy in the measurement of component X, and wherein the components of the measured values ​​P_A1 and P_A2 are components of a wavefront representation of the refractive error, their linear combination, or quantities derived therefrom. Furthermore, the present invention relates to methods and devices for manufacturing the spectacle lens and the series of spectacle lenses.