"Chromatic Vision Simulator" is an experience tool which simulates color vision of color vision deficiencies.

About 5% of men have difficultly distinguishing red and green, or recognizing dark red. Such color deficiency can be classified into three major categories: Protanope / Protanomal, Deuteranope / Deuteranomal and Tritanope / Tritanomal.

Color deficiencies are the inability to tell differences between some colors other people can easily distinguish. People with different types of color vision deficiency perceive colors differently. For example, individuals diagnosed as Protan or Deutan cannot perceive differences between red and green, and pink and cyan.

These color visions are predictable by calculating working of the cone cells that perceive colors to some degree.

"Chromatic Vision Simulator" makes a simulated image of each color vision type of dichromat from built-in camera or image file and shows you how people with a specific type of color deficiency see the world in real-time.

Main Functions

  • Real-time parallel simulation
    Supporting real-time parallel simulations of different types of color vision simultaneously. A parallel simulations mode shows two, three or four different simulated color vision image together within type C or dichromat color vision of type P, D and T together.
  • Universal application
    Lineups both versions for iOS devices (iPhone, iPad and iPod Touch) and Android devices.
  • Digital zoom (max 5x)
    5x digital zooming of simulated images is supported.
  • Image source
    Rear camera, Front camera (when supported) and image file in the "Photo Album" can be used.
  • Storing simulated images
    Simulated Images including double, triple and quadruple can be stored in the "Photo Album" with marking letters of color vision type.
  • Geotagging (location information)
    "Geometry tag" (geotag) can be saved in simulation images. A geotag is added when you use a location supported devices and allow it to use location data. (depending on "Settings".)


  • iOS version
    iPhone, iPad, iPod touch with iOS7.0 or later.
  • Android version
    Android devices with Android 5.0 (API level 21) or later and OpenGL ES2.0 or later. (There is a possibility of not working according to the model. )


  • A simulation algorithm is based on a proposal method of academic research described below.
    H. Brettel, F.Viénot, and J. D. Mollon: Computerized simulation of color appearance for dichromats, Journal of the Optical Society of America A, vol.14, no.10, pp.2647-2655 (Oct. 1997).
  • Simulated images by this software are predicted images of dichromat vision under specific condition with specific method and not necessarily accurate. There is an individual variation in color vision.
  • Although this application has the ability to simulate with the "Simulation Intensity", it is just a function which makes a simple linear interpolation image between the dichromat(the strongest color vision deficiency) simulation and normal vision (original), and it is not intended to simulate the vision of anomalous trichromat(weak color vision deficiency).


  • This application software was developed by Kazunori Asada (Ph.D. of Medical Science and Ph.D. of Media design), and is released free.
  • Acknowledgment:
    I wish to express my gratitude to Mr. Hirofumi Ukawa and Masataka Matsuda who helped development of the open-source version.

Screen Images

Type C (Normal Color Vision)

Type C (Common, Normal Color Vision)open image

Type P (Protanope)

Type P (Protanopre)open image

Type D (Deuteranope)

Type D (Deuteranope)open image

Type T (Tritanope)

Type T (Tritanope)open image