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Updated: Sep 11, 2025

Subjective Refraction Test Using a Smartphone for Vision Screening
Published on: October 18, 2024
Improving the estimation of the spherical equivalent subjective refraction using objective information on
Aina Turull-Mallofré1, Mikel Aldaba1, Jaume Pujol1
1Centre for Sensors, Instruments and Systems Development, Universitat Politècnica de Catalunya, Rambla de Sant Nebridi 10, Terrassa, 08222, Spain.
This study improved objective refraction prediction accuracy using machine learning models trained with accommodative response and optical quality data. The enhanced models achieved results comparable to subjective refraction, outperforming previous methods.
Area of Science:
- Ophthalmology
- Optometry
- Computer Science
Background:
- Machine learning (ML) and deep learning (DL) have shown limited success in predicting subjective refraction endpoints objectively.
- Accurate subjective refraction is crucial for optimal vision correction.
Purpose of the Study:
- To enhance the predictive accuracy of objective refraction measurements.
- To develop improved ML models incorporating accommodative response and optical quality data.
Main Methods:
- Trained linear regression models using normal equations.
- Utilized data from a Hartmann-Shack aberrometer and an autorefractor.
- Tested three models on 176 eyes.
Main Results:
- The best model significantly reduced mean absolute error by 40% compared to commercial autorefractometers.
- Achieved 95% limits of agreement with subjective refraction of ±0.54 D.
- Demonstrated performance approaching inter-examiner variability in subjective refraction.
Conclusions:
- Incorporating accommodative response and optical quality data substantially improves objective refraction prediction.
- The developed ML models offer a more accurate and reliable method for determining subjective refraction endpoints.
- This approach shows promise for advancing objective eye examination techniques.
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