Which photoreceptors mediate photopic vision?

• A. Cones
• B. Rods
• C. Rods and cones
• D. Ganglion cells

Answer: (A)

Photopic vision refers to seeing in bright light, where color and fine detail are discerned. This is carried by cones, the photoreceptors that require strong illumination and provide color information. Cones are densely packed in the fovea, giving high visual acuity, which is why bright-light vision is sharp and colorful. Rods, by contrast, work best in low light (scotopic vision) and are highly sensitive but do not convey color or fine detail. They’re more spread out in the peripheral retina, contributing to motion and light sensitivity at night. Ganglion cells aren’t photoreceptors; they’re downstream neurons that relay processed signals to the brain. So the photopic pathway is driven by cones.