Chapter 3.3, Problem 5PQ

Summary Introduction

Introduction:

The photoreceptor cells are the rod and cone cells. These are present at the rear of the retina. Rods and cones both are part of retina in the eyes that contain membranes packed among photopigments molecules that absorb light and initiate photoreception process.

Cones are photoreceptor cell present in human retina that has less photopigments; however, they are important in color vision. This structure isactivated when the light level is high called as photopic vision. Their outer segment is cones shaped and in human eyes, three types of cone cells are present. Each of them has slightly different photo-pigments. Particular wavelength of light activates each type of photo-pigments such as red, blue or green. The brain plays an important role to differentiate color according to the relative intensity of cones’ stimulation.