Color Blindness

genetic disorder

Color blindness is when light sensing receptors do not work properly

  • Single gene mutation located on X chromosome
  • First discovered by John Dalton in 1794, who described his own color blindness
  • Does not effect the life expectancy
The picture to the right shows the different types of color blindness and the vision associated with each type.


  • Color blindness affects a person's ability to see the difference between colors like red, green, blue, and yellow.
  • There are many different types and each affects the ability to see different colors.
The image to the right shows how color blindness can affect someone's ability to see colors on a stop light.


  • Caused by abnormal pigments on X chromosome
  • Recessive trait
  • Majority passed down
  • Also can be caused by physical or chemical damage to eye
  • Effects one in twelve men and one in two hundred women
To the right, an image is shown of how color blind people would view colored pencils compared to how the average person views colored pencils.

Diagnostic tests

  • Optometrists test color vision as a matter of routine
  • Isihara Plate test done for red and green color blindness
  • Most common for routine involving 38 plates of circles with irregular colors
  • Lantern test is used on train drivers or in marine and aviation jobs
On the right, an example of the Isihara plate test is shown.

Prevention and Treatment

  • Can take medications from doctor
  • Color filters or contact lenses can be used to enhance brightness
  • Many find this confusing
  • Color blind people often have trouble with daily life and cannot do many jobs
The image on the right shows an example of glasses a color blind person can purchase to try to enhance their vision.


  • Many different organizations available for certain types of color blindness
  • Some are, PA Association for the Blind, Colour Blind Awareness, and NAACBP, National Association for the Advancement of Color-Blind People
On the right is the logo for the Colour Blind Awareness association, one of many organizations that support color blindness.