Question

Name the cells of the retina and their respective pigments which get activated:

1. In the dark
2. In light.

Answer 1

Rods:

1. Capable of scotopic vision (low light levels), they have a low spatial acuity and do not mediate color.
2. Populated at the periphery of the retina, they are rod-shaped, facilitating vision during dim light/night.
3. These contain rhodopsin pigment rich in vitamin A responsible for night vision, hence making rods sensitive to light.

The cells of the retina and their respective pigments which get activated in the dark are rod cells that contain rhodopsin.

Cones:

1. Capable of photopic vision(higher light levels), they are responsible for high spatial acuity and responsible for color vision.
2. They are populated in the central fovea region and are mostly found in the retina.
3. They help to distinguish color and other fine details and are cone-shaped.
4. They are of three types – long-wavelength sensitive cones(L-cones), middle-wavelength sensitive cones (M-cones), and short-wavelength sensitive cones(S-cones).
5. These contain iodopsin pigment known as violet pigment.

The cells of the retina and their respective pigments which get activated in the light are cone cells that contain iodopsin.