Question

chapter 15 multiple choice question 51
1 part | -- of 1 point

the blind spot of the eye is caused by ______.

○ the macula lutea interrupts the nerve pathway
○ an absence of cones in the foveae
○ more rods than cones within the retina
○ an absence of photoreceptors where the optic nerve leaves the eye

Explanation:

To determine the cause of the eye's blind spot, we analyze each option:

• The macula lutea (fovea) is for sharp vision, not related to the blind spot's cause. Eliminate the first option.
• The foveae's cone absence relates to its function (cones for color/sharp vision), not the blind spot. Eliminate the second option.
• The rod - cone ratio in the retina affects light/dark and color vision, not the blind spot. Eliminate the third option.
• The blind spot occurs where the optic nerve exits the eye, and there are no photoreceptors (rods or cones) there to detect light, so this option correctly explains the blind spot.

Answer:

D. an absence of photoreceptors where the optic nerve leaves the eye (assuming the options are labeled A, B, C, D in order, with the last option being D)