Related Experiment Video
Updated: Dec 22, 2025

Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
Deep Learning-Based Prediction of Refractive Error Using Photorefraction Images Captured by a Smartphone: Model
Jaehyeong Chun1, Youngjun Kim2, Kyoung Yoon Shin2
1Department of Industrial and System Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
Background:
Accurately predicting refractive error in children is crucial for detecting amblyopia, which can lead to permanent visual impairment, but is potentially curable if detected early. Various tools have been adopted to more easily screen a large number of patients for amblyopia risk.
Objective:
For efficient screening, easy access to screening tools and an accurate prediction algorithm are the most important factors. In this study, we developed an automated deep learning-based system to predict the range of refractive error in children (mean age 4.32 years, SD 1.87 years) using 305 eccentric photorefraction images captured with a smartphone.
Methods:
Photorefraction images were divided into seven classes according to their spherical values as measured by cycloplegic refraction.
Results:
The trained deep learning model had an overall accuracy of 81.6%, with the following accuracies for each refractive error class: 80.0% for ≤-5.0 diopters (D), 77.8% for >-5.0 D and ≤-3.0 D, 82.0% for >-3.0 D and ≤-0.5 D, 83.3% for >-0.5 D and <+0.5 D, 82.8% for ≥+0.5 D and <+3.0 D, 79.3% for ≥+3.0 D and <+5.0 D, and 75.0% for ≥+5.0 D. These results indicate that our deep learning-based system performed sufficiently accurately.
Conclusions:
This study demonstrated the potential of precise smartphone-based prediction systems for refractive error using deep learning and further yielded a robust collection of pediatric photorefraction images.

