Which statement correctly describes the off-center sensitivity range for rods at night?

Which statement correctly describes the off-center sensitivity range for rods at night?

• A. 1-3° off center
• B. 2-4° off center
• C. 5-10° off center
• D. 4-12° off center

Answer: (D)

Rods drive night vision, and they’re densest away from the fovea. To detect faint lights or objects in low light, you don’t look directly at them; you use off-center vision so the image falls on the rod-rich area of the retina. The practical range where rods are still highly sensitive—and yet you retain usable detection—is about 4 to 12 degrees off center. If you look too close to the center, you’re relying on cones with lower low-light sensitivity. If you look much farther out, the rods’ density tapers and resolution drops, reducing detectability. So the statement that best describes night off-center sensitivity is approximately 4–12 degrees off center.

Rods drive night vision, and they’re densest away from the fovea. To detect faint lights or objects in low light, you don’t look directly at them; you use off-center vision so the image falls on the rod-rich area of the retina. The practical range where rods are still highly sensitive—and yet you retain usable detection—is about 4 to 12 degrees off center. If you look too close to the center, you’re relying on cones with lower low-light sensitivity. If you look much farther out, the rods’ density tapers and resolution drops, reducing detectability. So the statement that best describes night off-center sensitivity is approximately 4–12 degrees off center.