The day blind spot corresponds to which retinal structure?

The day blind spot corresponds to which retinal structure?

• A. Optic disc on retina - no photoreceptors; 5.5 to 7.5 degrees
• B. Fovea centralis
• C. Macula lutea
• D. Lens

Answer: (A)

The day blind spot is caused by the optic disc, the spot where the optic nerve exits the retina. That region has no photoreceptors (no rods or cones), so light hitting it cannot be detected, creating a physiological blind spot in daylight as well. The blind spot is located about 5.5 to 7.5 degrees in visual angle from the fovea, toward the temporal retina. The fovea centralis is the tiny, central part of the macula with a high density of cones for sharp vision, and the macula lutea surrounds it—both have photoreceptors and are not blind spots. The lens is not a retinal structure and does not determine the blind spot.

The day blind spot is caused by the optic disc, the spot where the optic nerve exits the retina. That region has no photoreceptors (no rods or cones), so light hitting it cannot be detected, creating a physiological blind spot in daylight as well. The blind spot is located about 5.5 to 7.5 degrees in visual angle from the fovea, toward the temporal retina. The fovea centralis is the tiny, central part of the macula with a high density of cones for sharp vision, and the macula lutea surrounds it—both have photoreceptors and are not blind spots. The lens is not a retinal structure and does not determine the blind spot.