Refractive Value Determination Using Radial Line Visual Stimulus

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Solution Overview

Problem

Existing methods for determining refractive values of the eye, such as the fan-and-block technique, require specialized equipment and trained professionals, limiting their accessibility and applicability on a global scale.

Innovation Solution

A method involving the display of a visual stimulus with concentric radial lines projected at different defocus planes, allowing the user to indicate the radial line of maximum sharpness, which is then used to determine refractive values such as spherical power, cylindrical power, and cylindrical axis without the need for specialized equipment or trained professionals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional fan-and-block technique is used, then measurement precision of refractive values is improved, but device complexity and requirement for trained professionals increases

Engineering Contradiction:
Improverefractive value determination accuracyVSAvoidequipment and professional training requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex physical optical equipment with a simplified digital copy - a display device showing radial line patterns that simulate the fan-and-block test. The digital stimulus reproduces the essential measurement function without requiring sophisticated optical instruments, thereby reducing device complexity while maintaining measurement capability.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent substitutes mechanical/optical systems with electronic/digital systems. Instead of using physical fans, blocks, and rotating lenses, the invention uses a display device to present radial line patterns and processes user inputs through algorithms to determine refractive values, eliminating the need for complex mechanical equipment and specialized training.

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

2Reliability

If specialized equipment and trained professionals are used, then reliability of refractive measurement is improved, but ease of operation and global accessibility deteriorates

Engineering Contradiction:
Improverefractive measurement reliabilityVSAvoidaccessibility without trained professionals
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent enables users to perform their own refractive measurements without requiring trained professionals. The system guides users through the process via display instructions, collects input responses, and automatically processes the data to determine refractive values, making the service self-sufficient and accessible to anyone with basic literacy.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent creates a universal measurement system that can be deployed in diverse settings without requiring specialized equipment or trained operators. The same display-based apparatus can be used in clinics, retail stores, or remote locations, serving multiple functions and user populations with a single standardized tool.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If conventional refraction methods are used, then measurement precision is improved, but loss of time and productivity increases

Engineering Contradiction:
Improverefractive value accuracyVSAvoidtime for subjective sight-test procedures
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent employs periodic presentation of radial line patterns at different orientations and defocus levels, allowing rapid collection of multiple data points in a structured sequence. This periodic stimulation enables efficient processing of refractive information through algorithmic analysis of user responses to the repeating stimulus patterns.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent replaces time-consuming manual procedures with automated digital processing. Instead of requiring professionals to manually interpret patient responses and calculate refractive values, the system automatically processes input data through algorithms, significantly reducing the time required from measurement to result while maintaining precision.

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

Data Source

PatentEP4555917A1Method and apparatus for determining at least one refractive value of an eye
Publication Date: 2025.05.21 CARL ZEISS VISION INTERNATIONAL GMBH
  • EP4555917A1 patent drawingFigure 1~2
  • EP4555917A1 patent drawingFigure 3~4
  • EP4555917A1 patent drawingFigure 5~6

AI summary

The present invention refers to a method (218), a computer program, and an apparatus (110) for determining at least one refractive value (216) of an eye (112) of a person (114) and to a related method (210) for producing at least one ophthalmic lens (212) for the eye (112) of the person (114). The method (218) comprises the following steps: a) (220) displaying a visual stimulus (120) to an eye (112) of a person (114), wherein the visual stimulus (120) comprises a plurality of concentric radial lines (126, 126,', ...), wherein each radial line (126, 126,', ...) has a different angular value (128, 128,', ...) with respect to a center (130) of the visual stimulus (120); b) (224) recording a reaction by the person (114) to the visual stimulus (120); and c) (226) determining at least one refractive value (216) of the eye (112) of the person (114) by evaluating the reaction by the person (114) to the visual stimulus (120), wherein step a) (220) comprises that each radial line (126, 126,', ...) is projected at a particular defocus plane to the eye (112) of the person (114), whereby a particular dioptric power is provided to the eye (112) of the person (114), and wherein step b) (224) comprises that recording the reaction by the person (114) to the visual stimulus (120) indicates that a particular radial line (144) at a particular angular value (146) has an appearance of maximum sharpness (148) to the eye (112) of the person (114).