Eccentric Photorefraction Image Simulation for Eye Refraction Estimation
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Solution Overview
Problem
Existing methods for estimating eye refraction, such as eccentric photorefraction, do not account for higher order aberrations and are often expensive, cumbersome, or difficult to use, particularly in non-professional settings.
Innovation Solution
A method and system using a set of eccentric photorefraction images, a simulation model, and an optimization algorithm to estimate refraction parameters like sphere, cylinder, and axis, utilizing a device with multiple light sources and an image capturing system, which includes a minimization algorithm to adjust parameters for accurate estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If automated infrared photoretinoscopy is used to measure astigmatism, then objective refraction measurement is achieved, but higher order aberrations are not taken into account and the device is expensive and cumbersome
Solution Approach 1:
The patent uses a simulation model that creates virtual photorefraction images based on optical parameters, replacing the need for complex expensive automated infrared photoretinoscopy equipment. The simulation copies the essential measurement functionality using simpler, more accessible components like a standard camera and light sources.
Solution Approach 2:
The invention changes the approach from direct physical measurement to parameter-based simulation. By adjusting optical parameters (sphere, cylinder, axis, higher order aberrations) in the simulation model and comparing simulated images with actual photographs, the system achieves accurate refraction measurement without requiring complex measurement equipment.
2Measurement precision
If professional auto-refractometers are used for refraction measurement, then accurate refraction estimation is achieved, but the systems are expensive and cumbersome
Solution Approach 1:
The system enables self-service refraction measurement where individuals can perform their own eye examination using a smartphone camera and the described method. The automated image processing and optimization algorithm allow non-professionals to obtain accurate refraction estimates without requiring trained operators or complex equipment.
Solution Approach 2:
The patent replaces professional auto-refractometers with a copy-based approach using standard smartphone cameras. By capturing photographs of the eye and processing them through the simulation model with optimization, the system replicates the functionality of expensive professional equipment using widely available consumer devices.
3Measurement precision
If eccentric photorefraction methods are used, then refraction measurement is achieved, but the methods are mostly theoretical and do not enable quick refraction measurements
Solution Approach 1:
The patent performs preliminary action by pre-establishing the simulation model with optical parameters before actual measurement. The model is prepared in advance with known relationships between parameters and photorefraction image characteristics, allowing rapid measurement execution without theoretical calculations during the actual measurement process.
Solution Approach 2:
The system uses feedback through the optimization algorithm that compares simulated images with actual captured images. The difference metric provides continuous feedback during the optimization process, enabling rapid convergence to accurate refraction parameters and achieving quick measurements in practice.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Provides quick, cost-effective, and easy-to-use refraction estimation, capable of accounting for higher order aberrations, suitable for non-professional use and mass screening.
Implementation Method 1
the plurality of M light sources being adapted and configured to illuminate the eye with a light pulse
Implementation Method 2
reflected light forms on the pupil in the detected image, a light shape with a complementary, non luminous shape, called dark crescent
Implementation Method 3
Generating a set of N simulated eccentric photorefraction images using a simulation model according to the values of the set of parameters
Data Source
Figure 1A~2
Figure 3~5
Figure 6~7
AI summary
The invention concerns a method for estimating refraction of an eye of an individual, comprising the following steps: a) Providing a set of N acquired eccentric photorefraction images of the eye; b) setting values for a set of parameters including at least sphere (110) ; c) Providing a set of N simulated eccentric photorefraction images (120) ; d) Determining an estimator of a difference between the set of N acquired eccentric photorefraction images and the set of N simulated eccentric photorefraction images (130) ; d) Performing an optimization using an optimization algorithm (140) so as to optimize said estimator by adjusting values for the set of parameters and iterating steps c) and d), and deducing an estimation of at least one refraction parameter of the eye.