Why are we unable to see images formed on the optic disc (blind spot) in the human eye?

• A. Because the optic disc is covered by the lens, blocking light from reaching it
• B. Because the optic disc is located in the peripheral retina, which is not sensitive to light
• C. Because the optic disc contains only rod cells and no cone cells
• D. Because the optic disc lacks photoreceptor cells such as rods and cones

Answer: (D)

Verified step by step guidance

1. Understand the anatomy of the human eye, focusing on the retina and the optic disc. The retina contains photoreceptor cells (rods and cones) that detect light and send visual information to the brain.
2. Recognize that the optic disc is the point on the retina where the optic nerve fibers exit the eye, and it does not contain any photoreceptor cells (rods or cones).
3. Since the optic disc lacks photoreceptors, it cannot detect light or form images, which creates a natural blind spot in our visual field.
4. Consider why the other options are incorrect: the optic disc is not covered by the lens, it is not specifically located in the peripheral retina, and it does not contain only rod cells.
5. Conclude that the inability to see images formed on the optic disc is due to the absence of photoreceptor cells, making it insensitive to light and resulting in the blind spot phenomenon.