Which cones are NOT located within the foveola?

Which cones are NOT located within the foveola?

• A. Red cones
• B. Blue cones
• C. Green cones
• D. Yellow cones

Answer: (B)

Blue cones are not located within the foveola. The foveola is the very center of the fovea and is designed for maximum visual acuity, with a dense, nearly pure population of cone photoreceptors arranged for fine detail. In this central region, the cones are predominantly long- and medium-wavelength sensitive—the red and green cones—while short-wavelength (blue) cones are extremely sparse or absent. The blue cones show up mainly in the surrounding retina (parafovea and periphery), where their signals contribute to color vision over a broader area but do not participate in the ultra-high-resolution sampling at the foveal center. So the cone type not present in the foveola is blue.

Blue cones are not located within the foveola. The foveola is the very center of the fovea and is designed for maximum visual acuity, with a dense, nearly pure population of cone photoreceptors arranged for fine detail. In this central region, the cones are predominantly long- and medium-wavelength sensitive—the red and green cones—while short-wavelength (blue) cones are extremely sparse or absent. The blue cones show up mainly in the surrounding retina (parafovea and periphery), where their signals contribute to color vision over a broader area but do not participate in the ultra-high-resolution sampling at the foveal center. So the cone type not present in the foveola is blue.