Which statement about the retina is true?

Which statement about the retina is true?

• A. Rods greatly outnumber cones
• B. Cones greatly outnumber rods
• C. They are equal in number
• D. Photoreceptors outnumber ganglion cells by a factor of 100

Answer: (A)

The key idea is the large difference in numbers between the two photoreceptor types. In the human retina, there are about 120 million rods and around 6–7 million cones, so rods outnumber cones by roughly 20:1. This massive predominance of rods explains why peripheral and low-light vision is so rod-dominated, while cones—though fewer and concentrated in the fovea—handle color and sharp vision in bright light. The statement that photoreceptors outnumber ganglion cells by about 100:1 is a broad generalization and, while true in rough terms, isn’t as central to the distinctive pattern of photoreceptor distribution. So the most characteristic truth is that rods greatly outnumber cones.

The key idea is the large difference in numbers between the two photoreceptor types. In the human retina, there are about 120 million rods and around 6–7 million cones, so rods outnumber cones by roughly 20:1. This massive predominance of rods explains why peripheral and low-light vision is so rod-dominated, while cones—though fewer and concentrated in the fovea—handle color and sharp vision in bright light. The statement that photoreceptors outnumber ganglion cells by about 100:1 is a broad generalization and, while true in rough terms, isn’t as central to the distinctive pattern of photoreceptor distribution. So the most characteristic truth is that rods greatly outnumber cones.