Deutan

The “second” type of colorblindness (after Protan; before Tritan) that acts as an umbrella term for Deuteranomaly and Deuteranopia. “Deuteran” would be the intuitive name, but this is never used. Deutan CVD is associated with the M-Cone and affects the red-green Opponent Channel (generally a weakening of the green stimulation).

Deutan defects are almost always Congenital and arise from mutations of the gene for the M-Opsin, either by shifting the Peak Wavelength higher (creating an M*-Opsin), or by rendering it inoperable.

The Colors of Confusion for Deutans are:

• Red / Orange / Yellow / Green / Brown
• Cyan-Green / White
• Blue / Purple
• Dark Green / Black

A Deutan is also an individual who has a Deutan defect.