Color vision is mediated by which photoreceptors in the retina?

• A. Cones
• B. Rods
• C. Bipolar cells
• D. Ganglion cells

Answer: (A)

Color vision comes from cone photoreceptors in the retina. Cones express three different visual pigments that are sensitive to different parts of the light spectrum—short, medium, and long wavelengths—which the brain combines to perceive a range of colors. They function best in bright light and are densely packed in the fovea, giving high resolution color detail. Rods, by contrast, are highly sensitive and handle vision in dim light but provide mostly black-and-white information. Bipolar and ganglion cells are neurons that pass signals from photoreceptors toward the brain; they’re part of the processing pathway, not the color-detecting cells themselves. So color vision is mediated by cones.