The Freiburg Vison Test, FrACT, now has gained contrast threshold assessment in its all-platform version FrACT₁₀. [An isolated version, allowing full-screen takeover, is here.] It is based on JavaScript and thus can run in any current browser on any platform, including large touch devices (online only).

At this time FrACT₁₀ has the following options

  • Visual acuity assessment using Sloan Letters, Landolt rings, Tumbling E, TAO (The Auckland optotypes) and Vernier acuity
  • Low-contrast acuity
  • Crowding options
  • Contrast threshold using Sloan Letters, Landolt rings or Tumbling E as optotype
  • Various sound feedback options with volume control
  • Various result formats (LogMAR, decimal, Snellen fraction)
  • Motivating “reward pictures” after last trial
  • Result export
    • via clipboard, ready to paste into a spreadsheet
    • automated file export
  • Operation on touch devices (tablets)
  • Contrast-validation test fields
  • An up-to-date manual
  • Development diligently versioned with git


What FrACT₁₀ doesn’t do as yet, but it’s being planned

  • Interactive gamma calibration
  • Gratings
  • Display transformation (mirroring, rotation)
  • Improvement of contrast values using dithering
  • Email export
  • Stand-alone app

For “production environments”, e.g. clinical studies, you should stick to the proven and “grandfathered” classic FrACT, currently at version 3.10.5.