A smartphone application may enable patients to obtain best-corrected visual acuity (BCVA) measurements that agree with clinically-obtained measurements and share them with clinicians, according to research published in the Journal of Optometry.

Investigators included 40 participants (age range, 21-71 years) in the analysis and performed visual acuity measurements to establish a clinical baseline prior to measuring with the smartphone application.  

The application prompts users to hold the device 30 cm from their face for calibration and then measures BCVA while the patient holds the device at a comfortable distance. Black Landolt rings are viewed with crowding on a white background and participants are forced to swipe in 1 of 4 directions to identify the smallest optotype they are able to resolve. The smartphone application initially displays letters at a 0.9 logarithm of the minimum angle of resolution (logMAR) optotype, and if the participant holds the phone too close to their face, a warning is displayed. Overall, the application measures BCVA 4 times per eye.

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The smartphone application obtained similar measurements to those obtained clinically for the right (P =.478) and left (P =.608) eyes. Overall, the mean difference in BCVA measurements for the right and left eyes were -0.009 and -0.005 logMAR, respectively.

However, the repeatability analysis found significant differences for right eye outcomes (P =.018) but not left eye outcomes (P =.102). Despite this finding, no significant differences in the Wilcoxon Man Whitney tests were observed between clinical and smartphone application measurements in either the right (P =.865) or left (P =.653) eyes.

These data indicated that the smartphone application may be an effective BCVA assessment tool, which may improve access to visual acuity evaluations for individuals lacking access to eye care.

“This has the potential to facilitate home monitoring for adult patients; however, further research is needed to validate the use in children,” according to the researchers. “The results have major implications in advancing telemedicine and providing ophthalmologists with a reliable and accessible method to measure [visual acuity] and communicate results remotely between providers and patients.”

Study limitations include a small sample size.  

Disclosure: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures..


Ogino M, Salmerón-Campillo RM, Hunter S, et al. Clinical validation of a novel smartphone application for measuring best corrected visual acuity. J Optom. Published online March 23, 2023. doi:10.1016/j.optom.2023.01.001

This article originally appeared on Optometry Advisor