Tritanopia

A rare type of colour vision deficiency caused by the complete absence of short-wavelength (blue) cone cells in the retina. People with tritanopia have difficulty distinguishing blue from yellow and blue from green. Tritanopia is much less common than protan or deutan CVD types and is therefore less frequently addressed in accessibility design tools, though designing simultaneously for tritanopia and protanopia is nearly as complex as designing for complete colour blindness.