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Subjective Refraction Test Using a Smartphone for Vision Screening
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Comparing the Netra smartphone refractor to subjective refraction.

Benoit Tousignant1, Marie-Christine Garceau1, Nikola Bouffard-Saint-Pierre1

  • 1School of Optometry, Université de Montréal, Montréal, QC, Canada.

Clinical & Experimental Optometry
|November 28, 2019
PubMed
Summary

The smartphone-based EyeNetra system, when used without professional help, significantly overcorrects myopia and reduces visual acuity and comfort compared to traditional methods. Professional refinement improves results but still falls short of standard subjective refraction.

Keywords:
diagnostic techniquesinstrumentationocularophthalmological instrumentationrefractive errorstelemedicinevision tests

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Area of Science:

  • Ophthalmology
  • Optometry
  • Digital Health

Background:

  • Smartphone-based systems offer potential for mobile eye care.
  • EyeNetra is a specific smartphone application for subjective refraction.
  • Evaluating novel digital health tools against established methods is crucial.

Purpose of the Study:

  • To compare the accuracy and user experience of the EyeNetra system against professional subjective refraction.
  • To assess visual comfort and participant preference for EyeNetra versus traditional refraction.
  • To determine the efficacy of a refined EyeNetra approach.

Main Methods:

  • A randomized, double-blind study involving 36 optometry-naïve participants (18-35 years).
  • Three refraction methods were tested: professional subjective refraction, unassisted EyeNetra, and practitioner-refined EyeNetra.
  • Visual acuity (logMAR), subjective preference, and visual comfort were measured via questionnaires.

Main Results:

  • Unassisted EyeNetra resulted in significant myopic overcorrection (median 0.60 D) and lower visual acuity compared to professional refraction.
  • Refined EyeNetra showed improvement but remained more myopic than professional subjective refraction.
  • Participants overwhelmingly preferred professional subjective refraction for visual outcomes and comfort.

Conclusions:

  • The EyeNetra system, particularly unassisted, leads to substantial myopic overcorrection and reduced visual performance.
  • Professional refinement of EyeNetra partially mitigates issues but does not match standard subjective refraction.
  • Current smartphone-based refraction technology requires further development for clinical reliability and user satisfaction.