ColorDx® CCT HD®

Key Features

Researched, developed, and tested by the US Air Force, Global Allied Partners and Konan Medical

Defines the highest measure of color vision performance for aviation, aerospace and other high visual-demand medical and vocational applications.

Serious Clinical Tools

For Ophthalmology and Optometry

routine clinical testing that is easy to administer but yields powerful functional vision data

Clinical Trials

Safety / Efficacy Data

a sublime new tool to augment clinical research discovering and documenting functional vision changes over time

Konan ColorDx CCT-HD 4 button response pad

Easy Testing - 4 Button Response Pad

Konan’s 4-button USB response pad provides a robust ambidextrous response solution

benefits ...

  • Facilitates maintaining fixation near the  test area
  • Reduces uncontrolled contrast adaptation and response time variability due to visual searching for the response character
  • No inadvertent testing of keyboard / mouse skills, or hunting for one of 10 letters when the focus should be on taking the test

High Granularity

CCT HD provides highly granular cone-isolation contrast steps for discrete, scalar scoring.

Patient color vision trends analysis

Automatically compare exam results with prior data collected on the same patient

benefits ...

to clearly, graphically, and numerically see changes in cone-isolated results (both threshold and Standard Error) over time.  A new standard for clinical research, clinical trials, and routine patient monitoring of acquired color deficiencies

CE mark and FDA listed

The first and only FDA listed and CE marked cone-isolation contrast sensitivity test for color vision diagnostics

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from Konan Medical USA, an ISO-13485 company.

Robust Psi-marginal Adaptive Threshold and Error Estimation

Powerful Bayesian psychometric function for both threshold and error estimation

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  • Published technique that has wide academic use
  • Estimates contrast threshold and slope virtually free of bias
  • Calculation of ”guess rate” from the posterior distribution
  • Addresses nuisance parameters in an adaptive manner
  • Background calculation of next ‘look-ahead” of calculated trials based on distribution of prior answers
  • Shown to give higher precision in the threshold estimate when the threshold is designated to be the only parameter of primary interest and the slope and the lapse rate are treated as nuisance parameters

The Low Contrast Ceiling is Lifted

The original CCT was technically limited to testing down to ~ 1.0 % contrast, but this is far above the human performance threshold

benefits ...

  • Subjects were ”binned” into 5 basic threshold levels, the lowest of which contained the majority of responses
  • There is significantly more performance data uncovered by testing to < 0.3 % contrast with highly granular contrast steps down to ~ 0.25%.
CCT-HD isolated cone contrast sensitivity

Photopic Cone Isolation

Color cone receptors (L, M, and S-cones) are active under photopic conditions.

benefits ...

  • Common ophthalmic tests specifying photopic conditions are variously conducted generally in the range of ~ 85 cd/m²
  • CCT HD provides background luminance in the mid photopic range

Co-developed with USAF

Developed and licensed in collaboration with United States Air Force School of Aerospace Medicine and OBVA (Operation Based Vision Assessment) laboratory team under CRADA

benefits ...

to create the new gold standard for color vision diagnostics.

OBVA allied partners testing cone-isolation contrast sensitivity

5+ years in development by US Air Force OBVA including global allied contributors …

benefits ...

to evaluation / clinical validation from:


  • Singapore, Australia, Canada, Israel, NAMI, USAARL, University of Melbourne, University of Waterloo, York University
  • Effect of hypoxia on color vision – Japan

Adaptive fast testing or Full Threshold

“Adaptive” method initiates with a stimulus sequence about one-half the number stimuli of “Full Threshold”  ~1 to 2 minutes total for typical patients.

benefits ...

If at the end of the adaptive sequence, the score is below the Pass/Fail criteria, the test seamlessly continues through full threshold testing, only for the individual cone population(s) less than Pass/Fail.  Full Threshold is designed to minimize the “Standard Error” of the determined threshold.

Response Time as Secondary Performance Measure

Response times can be an interesting secondary metric of subject performance

benefits ...

As examples, individuals with poor sensitivity for a cone population would be expected to struggle and take more time to try to accurately identify the stimulus direction.  Poor cone-isolation contrast sensitivity would be expected to have long response times. The contrary, poor scoring on cone-isolation contrast sensitivity accompanied with very fast test times may indicate purposeful random responses and / or disinterest in proper test administration. 

Smart, Deep Synchronous Calibration

A novel, synchronous calibration method designed specifically for CCT HD

benefits ...

is used to custom-calibrate an IPS display to characterize the display card and display as a system.


  • Reliable cone contrasts tested at less than 0.2% are required to eliminate the contrast ceiling of the original CCT and challenge the true thresholds of human vision
  • Periodic in-office calibration are alerted to the user once per month and the last calibration or verification date is printed on the exam report. Importantly, CCT HD does not fully stop use of the system until recalibration is completed (triggered by the lapse of a single calendar day). The calibration process only takes minutes.

Secure 256-bit encrypted patient data

Today’s medical records, at the minimum, require secure encryption.

benefits ...

  • CCT HD uses 256 bit encryption with admin and user-specific user names and passwords.
  • CCT HD also features permission-based remote training and service as well as one-button software updates.

Solid– Secure – Robust from Konan Medical

Language and literacy neutral, no character bias, Landolt C

L, M, and S cone contrast thresholds are tested using a Landolt C

benefits ...

presented in one of 4 cardinal directions:  Left – Up – Right – Down and simply answered by depressing an arrow button in the same direction.


A secondary measure, response timing, is also recorded and averaged for set of cone trials, with the guideline that slow response are expected to accompany difficulty in seeing the targets, and fast, confident responses are expected with normal color vision.

Easy to administer Easy to take

Low Sensitivity to Viewing Angle

IPS LCD displays provide limited changes in brightness and color irrespective of the viewing angle

benefits ...

to produce accurate low contrast cone isolation, without which, precision of testing may suffer.

Clear Auditory Feedback

User experience is further improved by auditory feedback

benefits ...

implemented using pleasing, language-neutral tonal feedback with each response. Auditory feedback uses high – low tones (default) intuitively signaling correct-incorrect responses, but with operator-set options for single tone (no correct-incorrect significance) or turned off.

Robust, beautiful reporting

On-screen | printed | PDF richly illustrated reports including on-screen help and tool tips

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are provided with routing features to select EMR systems. Print / PDF reports may be customized with clinic name and logo.

Monocular and Binocular Test Strategies & Scoring

Binocular summation increases visualization efficiency of the low contrast targets

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CCT HD provides separate score criteria for binocular Vs. monocular testing. Most color vision testing should be performed monocularly.

Illustrated Help

Richly illustrated help screens accessed with a touch of a button

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to clearly and graphically get additional detail on results, reports and data

Fully automated incremental backup

Incremental backups are seamless executed in the background with no operator action

benefits ...

allows lightning fast data archiving to local or network drives. User initiated full backups also available from Preferences.

Service-Defined Pass / Fail Criteria

For military customers, CCT HD ships with US Air Force and US Navy cut-off criteria

more …

Matte Testing Monitor to Enhance Results Sensitivity

CCT-HD matte screen attenuates virtually all unwanted glare sources that obscure visualization of critical detail, depressing test scores.



Konan's priority in this unprecedented situation is the health and safety of our employees and their families. We are  following official guidance to minimize the spread of COVID-19 and have adjusted operations accordingly. We are open to serve our customers.


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