Blind spot is due to optic nerve exit.

Blind spot is due to optic nerve exit.

• A. Optic nerve exit
• B. Fovea absence
• C. Cornea curvature
• D. Lens shape

Answer: (A)

The blind spot comes from the optic nerve exiting the eye. Where the optic nerve (the optic disc) leaves the retina, there are no photoreceptors—rods or cones—so light hitting that tiny area isn’t detected. That gap on the retina translates to a blind spot in the corresponding part of the visual field. The other options don’t explain a blind spot. The fovea is a region of high acuity with many cones, not an absence of photoreceptors, so its lack wouldn’t produce a blind spot. The curvature of the cornea and the shape of the lens affect how light is focused onto the retina (refraction), influencing focusing and refractive errors rather than creating a retinal patch with no photoreceptors.

The blind spot comes from the optic nerve exiting the eye. Where the optic nerve (the optic disc) leaves the retina, there are no photoreceptors—rods or cones—so light hitting that tiny area isn’t detected. That gap on the retina translates to a blind spot in the corresponding part of the visual field.

The other options don’t explain a blind spot. The fovea is a region of high acuity with many cones, not an absence of photoreceptors, so its lack wouldn’t produce a blind spot. The curvature of the cornea and the shape of the lens affect how light is focused onto the retina (refraction), influencing focusing and refractive errors rather than creating a retinal patch with no photoreceptors.