ColorDx® CCT HD®

High-Precision Diagnostic Color Vision Testing

The new gold standard in diagnostic color vision testing

Developed in collaboration with the U.S. Air Force School of Aerospace Medicine OBVA (Operational Based Vision Assessment) laboratory under CRADA, CCT HD expands on the strengths of the original USAF cone-isolation contrast test (Rabin CCT) and is built from the ground up with entirely new architecture.

    Highlights include:

  • Cone-isolation contrast sensitivity methodology
  • Expanded low-contrast range testing
  • "Landolt C" based test strategies
  • Simple to use 4-button response pad
  • Konan custom-calibrated IPS matte display technology
  • Rapid, intuitive, staged calibration
  • High fidelity cone-contrast granularity
  • Expansive illustrated reporting
  • Auto trends analysis
  • Contrast Sensitivity (achromatic) with auto AUC calculation

Color vision and contrast sensitivity are important functions of the visual system, which may be affected by many diseases, disorders and common drugs and substances.

Understanding if and how much visual function is affected may assist clinical decision making and augment conversations with your patients.

Fundamentals of Cone-isolation Contrast Sensitivity

CCT HD is based upon the principle of stimulating individual cone type populations, L-cone (long wavelength), M-cone (medium), and S-cone (short). Each cone population has offset peak sensitivities and broad ranges of sensitivities. Although L-cones are often referred to as "red", M-cones as "green", and S-cones as "blue", peak sensitivity wavelengths of the cone populations are colors not fitting these descriptions.

CCT HD tunes the calibrated stimulus color composition to simultaneously maximize the response of a targeted cone population, minimize, as negligible, the response of non-targeted cones, and neutralize achromatic (brightness) cues.

L-cones have the best sensitivity of the 3 cones for "red" wavelengths, but with a peak sensitivity that is not "red". M-cones have strongest sensitivity for "green" wavelengths and S-cones have the strongest sensitivity for blue and violet wavelengths. There is little wonder why many emergency vehicles are colored in the range of the peak sensitivity of the largest cone populations where there is the highest sensitivity from our central vision.