[Visual acuity measured via the Freiburg visual acuity test (FVT), Bailey Lovie chart and Landolt Ring chart]

Klin Monbl Augenheilkd. 2002 Sep;219(9):660-7. doi: 10.1055/s-2002-35168.
[Article in German]


Introduction: If different ways for correcting refractive errors of the human eye have to be compared, accurate and reproducible measurement procedures are necessary.

Methods: Binocular visual acuity of 130 students without pathologies was measured with the Freiburg Visual Acuity Test, the Bailey-Lovie chart and a Landolt ring chart (4 orientations). The reproducibility of the FVT was determined by repeated measurements.

Results: The average visual acuity was 1.93 +/- 0.03 (= 20/10.4) with the FVT, 1.82 +/- 0.03 (= 20/11) with the Landolt ring chart, and 1.48 +/- 0.02 (= 20/13.5) with the Bailey-Lovie chart. 50 % of all repeated measurements with the FVT were within an interval of +/- 0.035 logMAR from the mean value. 95 % were within +/- 0.1 logMAR. Results of earlier studies are discussed.

Conclusion: On average, visual acuity values found with the Freiburg Visual Acuity Test were slightly larger as compared to the Landolt ring chart (difference = 0.025 logMAR). Taking the maximal difference of 0.05 logMAR tolerated by the international standard DIN EN ISO 8597 into account, both tests are equivalent. The results found with the Bailey-Lovie chart were substantially lower as compared to the Landolt ring chart (difference = 0.09 logMAR). The Freiburg Visual Acuity Test has a high reproducibility and measures visual acuity on a continuous scale that is not limited to the traditional visual acuity steps. Thus, it can be recommended as a reference procedure for comparative visual acuity studies.

Publication types

  • Comparative Study
  • English Abstract

MeSH terms

  • Adult
  • Diagnosis, Computer-Assisted / instrumentation
  • Diagnosis, Computer-Assisted / statistics & numerical data*
  • Female
  • Humans
  • Male
  • Reference Standards
  • Refraction, Ocular
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Vision Tests / instrumentation
  • Vision Tests / statistics & numerical data*
  • Vision, Binocular
  • Visual Acuity*