Tritanopia is a rare form of colour blindness in which a person's eyes are unable to receive the blue light part of the colour spectrum. If a person can still see some blue light then it is considered only a weakness known as Tritanomaly.
Listen to how the word sounds:
How does this happen?
In order to view colour the eye has special receptors called rods and cones. As we can see in this diagram, when a person has Tritanopia they are lacking the short-wavelength sensitive retinal cones (S-cones). The brightness of blue, indigo and a spectral violet is much reduced. Some of these colors become even as black. Yellow is indistinguishable from white, and purple colors are perceived as various shades of red. A person with normal vision can distinguish 7 hues while a person who has Tritanopia may only be able to distinguish 2 or 3 hues.
Who can have Tritanopia?
Unlike Deuteranopia or Protanopia, Tritanopia is not sex -linked, or not passed on through the X-chromosome. However, its defects are autosomal and hereditary and encoded on chromosome 7. Therefore women and men have the potential to be equally affected. It is also a disease that can be acquired during one’s lifetime. Though if acquired it is possible that it can be reversed. Acquired Tritanopia can happen in the following ways:
- hard hit on your head
- eye aging
- consuming alcohol
- use of some organic solvents
Tritanopia is a rare type of colourblindness. About 1% of males have Tritanopia or a form of Tritanomaly and for females it is about 0.01%.
What are the colour-related hazards?
While people with Tritanopia may have less difficulty with colour tasks than other people with colour blindness there are still dangers. Red and Green are not as great a concern but seeing yellow or when darker colours appear almost black can be an issue. How many road signs can you think of that have blue or amber?