Visual Field Measurement Using Multi-Distance Target Recognition
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Solution Overview
Problem
Existing visual field measurement techniques do not account for variations in focal length of the eye, leading to inaccurate assessments of a person's visual field.
Innovation Solution
A method that measures the visual field by arranging a target object at a specific distance and position, and symbols at multiple locations, determining the visual field based on the subject's ability to recognize these symbols while focusing on the target.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visual field measurement is performed using a fixed method (irradiating windshield with light), then the measurement process is simple, but the measurement precision is insufficient due to not accounting for individual focal length variations
Solution Approach 1:
The patent changes the measurement parameters by introducing multiple target distances (near, intermediate, far) and multiple symbol positions around the target object. This allows the measurement to account for individual focal length variations and accommodate different viewing conditions, thereby improving measurement precision without requiring complex additional equipment
Solution Approach 2:
The visual field measurement is segmented into multiple measurement points around the target object (e.g., upper, lower, left, right positions). By measuring visibility at each segmented position and synthesizing the results, the system achieves comprehensive visual field assessment with higher precision while maintaining procedural simplicity
2Measurement precision
If visual field measurement accounts for individual focal length differences, then the measurement precision improves, but the ease of operation decreases due to requiring multiple arrangements and measurements
Solution Approach 1:
The measurement system uses a universal target object that can be positioned at multiple standard distances (near, intermediate, far) and has multiple symbol positions arranged around it. This multi-functional design allows the same basic setup to accommodate different focal lengths and viewing conditions, improving precision while keeping the procedure standardized and easy to follow
Solution Approach 2:
The target object and symbols are pre-arranged at multiple predetermined positions and distances before the measurement begins. This preliminary preparation eliminates the need for complex real-time adjustments during measurement, maintaining ease of operation while enabling precise measurement across different focal length conditions
Data Source
AI summary
A method for measuring a visual field of a subject includes arranging a target object at a position at a measurement target distance from the subject and arranging a symbol at a plurality of positions around the target object and determining the visual field of the subject based on a position of the plurality of positions at which the subject can visually recognize the symbol while looking at the target object.