Trichromacy
Trichromacy is a really common type of inherited colour blindness. It happens when one of the three cone pigments is changed in its spectral sensitivity. This results in an impairment of normal 3D colour vision.
- Protanomaly is a mild colour vision defect where an altered spectral sensitivity of red retinal receptors makes it difficult to distinguish between red and green. It is hereditary and present in 1% of males.
- Deuteranomaly, caused by a similar shift in the green retinal receptors the most common type of colour vision deficiency. It slightly affects the ability to distinguish red and green in 5% of European males. It is hereditary.
- Tritanomaly is a rare form of colour blindness affecting blue to green and yellow to red discrimination. It's not sex-linked, so both boys and girls can have it