Question

The surface of retina has about $125$ million light sensitive

• A. rods only
• B. cones only
• C. rods and cones
• D. neither rods nor cones

Answer 1

The correct option is A

rods only

Explanation

1. The light-sensing cells in the retina are called photoreceptors.
2. Rods and cones are two important types.
3. Rod cells are specialized neurons that convert visual stimuli such as photons (light particles) into chemical and electrical stimuli that the central nervous system can interpret.
4. They are responsible for sensing the size, shape, and brightness of visual pictures and are triggered by light of various intensities.
5. Color and fine detail perception are duties handled by the other primary type of light-sensitive cell, the cone.
6. Rod cells are both more sensitive to light and more abundant than cone cells.
7. There are 125 million rods and around 6 million cones in each human retina.

So, the correct answer is option (A).