Final answer:
Cones are responsible for visual acuity, enabling us to see fine details and colors in bright light. Rods are responsible for scotopic sensitivity, allowing us to see in low light conditions but only detecting shades of gray.
Step-by-step explanation:
The phenomenon described in the question is related to the distribution of rods and cones in the retina. Cones are responsible for visual acuity and enable us to see fine details and colors in bright light. Rods, on the other hand, are responsible for scotopic sensitivity and allow us to see in low light conditions, although they only detect shades of gray.