Book Definition: Typically a genetic disorder (although sometimes the result of trauma) prevents an individual from discriminating certain colors. The most common form is red-green color blindness.

In Your Own Words

  • Not being able to see certain colors the usual way.
  • A severe difficulty in identifying a color.
  • Not being able distinguish different frequencies of color
  • Colorblindness can be a result of multiple seperate things. Most commonly it is a disbaility within the cones of your eyes, which may fire the wrong message to the brain when stimulated by color. This is why red-green colorblindess is common, the person's cones are simply malfunctioning. This can happen with any contrasting colors, colors which share similar cones but send 2 different images based on stimulis. Damage from trauma or birth defect can also impair the occipital lobes, meaning that your eyes work fine and can process color, your brain simply cant interpret the messages of color it is sent.


  • Some people cannot see green and red together. They can see green and red as individual colors, but if the two colors are next to each other, a red-green colorblind person will not be able to distinguish the boundary between the two colors.
  • A science teacher had a green sweater with a red stripe on it. He was red-green colorblind, so he didn't figure out his sweater had a red stripe until someone told him!
  • If you have extreme trouble distinguishing the numbers in one of the pictures below or are not able to see them at all
  • There are methods, techniques, and special glasses that may help people with color blindness differentiate different colors but not truly see them

external image colour_test.jpg

Additional Resources

Color blindness link: