Here's another answer for you. No Back to top 2. In the retina of our eye are photoreceptors that are sensitive to light. When light is absorbed by the photoreceptors, the light energy is converted into electrical and chemical signals that the neurons in our eye and brain process. Rods mediate vision at lower levels of illumination.
Cones mediate vision at higher levels of illumination.
There are three types of cones with each type differentially sensitive to a different region of the visible spectrum. For example, very short wavelength light can uniquely stimulate the S-cones but the sensation associated with this light stimulation has a reddish and bluish component. Fundamentally our color vision derives from comparisons between the amount of light being absorbed by each cone type. Our visual system compares the outputs of the cone types to process color. In addition, color appearance is influenced by the ratios of cone excitations in surrounding regions and by the overall levels of cone excitation caused by the prevailing illumination.