On-going studies should stay with the previous version.


The latest version (2021-05-04) of the Freiburg Vison Test FrACT₁₀ has the following changes:

  • The ceiling “max. reported decVA” value is now consistently applied to all formats (LogMAR, decimal & Snellen fraction). [Unchanged: exported data never has a ceiling applied.] Thanks to Jason S. Ng and his students for alerting me.
  • The “threshold correction” is now consistently applied to all formats and for export.
  • Biggest change: a measure of dispersion for the acuity result can now be calculated and displayed. Check the pertinent box in the “Formatting” section of Acuity Settings. The calculation is based on the non-parametric confidence interval¹, obtained by resampling 10,000× with replacing².

You can find it here.

Future plans:

  • Write paper on the confidence interval, update manual
  • Dithering for contrast
  • Make it open source.

¹See, for instance:
Wichmann FA, Hill NJ (2001) The psychometric function: II. Bootstrap-based confidence intervals and sampling. Perception & Psychophysics 63:1314–1329. DOI

²2021-05-04 Changed sampling n from 3000 to 10000, after finding that iPads and even iPhones do the calculation in less than a second.