Screen-Based Pupillary Distance Measurement for Infinity Vision

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Solution Overview

Problem

Current online methods for measuring pupillary distance, such as inter-pupillary distance and monocular pupillary distance, are inaccurate due to the assumption of an average eye curvature radius and the difficulty in estimating the convergence distance, leading to poorly adapted lenses that cause ophthalmic discomfort.

Innovation Solution

A method and system using an image acquisition unit attached to a screen, where the individual looks at an object displayed on the screen to simulate infinity, with real-time alignment and image processing to accurately determine pupillary distances by calibrating pixel dimensions with known object dimensions, and using facial recognition and optical character recognition algorithms to locate specific features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the individual looks at the camera of computer or tablet for online measurement, then the measurement process is simple and accessible, but the measured inter-pupillary distance corresponds to intermediate vision and is shorter than the actual distance at infinity

Engineering Contradiction:
Improveease of online measurementVSAvoidinter-pupillary distance accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent changes the viewing distance parameter by displaying the fixation target on a screen positioned at a specific distance from the user's eyes, and instructs the user to look at the target as if it were at infinity. This parameter change allows the measurement system to capture the eyes in a state that simulates distance vision, thereby obtaining accurate inter-pupillary distance measurements while maintaining the convenience of home-based testing.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If correction methods using average eye curvature radius are applied, then the measurement process remains simple, but the corrected measurements are still not accurate enough due to individual variations in eye curvature

Engineering Contradiction:
Improvesimplicity of correction methodVSAvoidpupillary distance accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent employs feedback mechanisms by capturing images of the user's eyes, analyzing the position and orientation of each eye relative to the fixation target, and using this information to calculate the inter-pupillary distance. The system continuously monitors the user's gaze direction and eye position, providing real-time feedback that allows for accurate measurement even when the user's eyes have individual curvature characteristics that differ from the average.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If the individual takes own measurements at home, then accessibility and convenience are improved, but the individual cannot accurately simulate looking at infinity which is essential for accurate measurement

Engineering Contradiction:
Improveaccessibility of self-measurementVSAvoidsimulation of infinity vision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces a fixation target displayed on a screen as an intermediary element between the user and the measurement process. This intermediary serves multiple functions: it provides a visual reference point for the user to focus on, simulates the effect of looking at infinity by being positioned at an appropriate distance, and enables the capture system to accurately determine eye position and orientation. This intermediary allows individuals to perform accurate measurements at home without requiring specialized equipment or professional assistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3415078B1Method and system for determining a pupillary distance of an individual
Publication Date: 2026.04.29 ESSILOR INTERNATIONAL(COMPAGNIE GENERALE D OPTIQUE)
  • EP3415078B1 patent drawingFigure 1
  • EP3415078B1 patent drawingFigure 2~3
  • EP3415078B1 patent drawingFigure 4a~6b

AI summary

A method for determining a pupillary distance of an individual (2), comprises the following steps: - displaying an object on a screen (15) located in front of the individual (2), the displayed object (17a) being positioned at a location in front of one eye (19a) of the individual (2), - instructing the individual (2) to look with at least said eye (19a) at said displayed object (17a), - acquiring at least an image of a part of the body of the individual (2) including said eye (19a), - determining the location of a plurality of specific features in the acquired image, one of the specific features being a pupil (3a) of said eye of the individual (2), - calculating the pupillary distance based on the location of the plurality of specific features. A corresponding system is also described.