Study Supports Voice-Guided Subjective Refraction Device

Eye Examination For Children. Ophthalmology. Auto refractometer
Researchers say an AI device’s refraction nerely matches an optometrist’s results.

With a telemedicine setting in mind, researchers presenting at the American Academy of Ophthalmology 2020 meeting sought to evaluate the accuracy of the Vmax voice-guided subjective refraction (VASR) machine. This machine is described as patient driven and uses artificial intelligence (AI) to guide the patient through the exam process. 

A study was conducted with 50 participants, evaluating both eyes for each participant (100 eyes total). Everyone included had a visual acuity (VA) correctable to 20/25 or better. 

All participants received a refraction by both VASR operated by a technician with no prior refracting experience and an optometrist using a phoropter. To compare statistics, the researchers used the Wilcoxon signed rank test. 

They were able to show that the  VASR machine was as accurate as an optometrist in performing a manifest refraction. There were no significant differences in manifest refraction between the 2 methods in terms of sphere (OD: P =.27; OS: P =.24), cylinder (OD: P =.34; OS: P =.23), axis (OD: P =.60; OS: P =.33) or spherical equivalent (OD: P =.34; OS: P =.23). The median VA for the VASR (-0.1OD, 0.0 OS logMAR) was essentially equivalent to that of the optometrist (0.0 OD, 0.0 OS logMAR) (P < .01).

As telemedicine expands, practitioners’ access to accurate technology can increase individuals’ access to quality care remotely. These findings support the potential for the VASR machine to be a valuable tool, especially in telemedicine. 


Binder N. Validation of a novel ai-guided manifest refraction tool for use in telemedicine. Presented at: American Academy of Ophthalmology 2020 Annual Meeting; November 13-15, 2020. Abstract PO318.

This article originally appeared on Ophthalmology Advisor