title: Effectiveness of a smartphone application for testing near visual acuity.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the discrepancy between the near visual acuity (VA) measurements using the EyeHandBook smartphone application and the conventional method of using the near vision card.
  
  
  METHODS
  Using similar environmental/examinational conditions, near VA measurements were obtained and compared using the near vision card and the EyeHandBook app for IPhone 5 from 100 subjects. The obtained data were changed to LogMAR format and the relationship between the two techniques was analyzed by paired sample t-test and scatterplot.
  
  
  RESULTS
  With a P-value of<0.0001, our results indicate that the EyeHandBook application running on IPhone 5 overestimates the near VA compared with the conventional near vision card by an average of 0.11 LogMAR unless the measurement done by the near vision card was 20/20.
  
  
  CONCLUSIONS
  Owing to vast utilization of portable high-definition screens in VA measurements, eye-care providers have to be mindful of the potential disparity in VA measurement between different platforms, which in our study was likely secondary to the high contrast and brightness levels of the smartphone's high-definition screen when compared with the near vision card.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: S
authors.initials: S
authors.lastname: Tofigh
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: E
authors.initials: E
authors.lastname: Shortridge
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: A
authors.initials: A
authors.lastname: Elkeeb
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: B F
authors.initials: BF
authors.lastname: Godley
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D015203:Reproducibility of Results; D000068997:Smartphone; D014787:Vision Tests / Q000295:instrumentation*; D014792:Visual Acuity / Q000502:physiology*