Mateo has trouble seeing colors because the cones in his eyes do not work properly. When Mateo does see color, he sees primarily in blues, yellows, and shades of gray and confuses reds and greens. Mateo suffers from

• A. sex-linked inherited color blindness.
• B. trichromatic vision.
• C. monochrome color blindness.
• D. dichromatic vision.

Answer: (D)

Verified step by step guidance

1. Understand the role of cones in the human eye: Cones are photoreceptor cells in the retina responsible for color vision. There are three types of cones, each sensitive to different wavelengths of light corresponding to red, green, and blue colors.
2. Identify the symptoms described: Mateo primarily sees blues, yellows, and shades of gray, and confuses reds and greens. This suggests a deficiency in perceiving certain colors.
3. Recognize the types of color blindness: Monochrome color blindness means seeing no color at all, only shades of gray. Trichromatic vision is normal color vision. Dichromatic vision involves having only two types of functioning cones, leading to difficulty distinguishing certain colors.
4. Match the symptoms to the type of color blindness: Mateo's confusion with reds and greens and his ability to see blues and yellows suggest he has two functioning types of cones, likely missing the red or green cone, which is characteristic of dichromatic vision.
5. Conclude that Mateo's condition aligns with dichromatic vision, as he exhibits the typical symptoms of this type of color blindness, where one type of cone is non-functional, leading to difficulty distinguishing between certain colors, such as reds and greens.