deuteranopian
Deuteranopian refers to a person who has deuteranopia, a type of red-green color vision deficiency. In deuteranopia, the medium-wavelength cone photoreceptors (M-cones) are absent or nonfunctional, which impairs discrimination between greens and reds. People with this condition often perceive greens as beige or gray and may confuse certain color hues, especially those with similar luminance, such as brown and green. The condition is typically congenital and inherited in an X-linked recessive pattern; it mostly affects males, while females are usually carriers with milder or no symptoms. The underlying genetic basis involves rearrangements or mutations affecting the OPN1MW gene that encodes the M-cone photopigment, though the specific mutation can vary.
Diagnosis is usually by color vision tests such as the Ishihara plates, the Farnsworth-Munsell 100-Hue test,
Prevalence estimates vary by population but are commonly cited as about 5% of males of Northern European