Man as a specie of higher intelligence has been evolving over the years according to evolution the closest species to man is the primate. In evolving man's vision also evolved since it was essential in our survival process. In evolving man ended up with color vision, and this color vision contribute to our lives in a lot of way including identifying threats, source of foods and navigate our way around. Color vision also provides us with contrast, in looking at how the eye uses color vision we would be look at the retina cells responsible and the some theories that surround the process.
####Color Perception
What we see or perceive is based on the light rays that are reflected from the object we are seeing as it goes through the visual pathway and is interpreted by the brain and the nature of our retina thus the properties of the rods and cones in the eye. This goes to confirm the color illusion theory which suggest that the world is colorless and that color is as a result of neurons or neural interpretation.
In understanding color we have to take into account the wavelength of light or the visible spectrum which contains the colors that are visible to the eye. Thus the color that we see or is reflected from an object has to fall within this wavelength to be appreciated by the eye or interpreted by the cells responsible, what this means is also that color changes with a change in wavelength. Color can also be appreciated based on its intensity, purity and the form. These are all based on the wavelength of light that falls on the eye, thus it would determine whether the eye sees green (a wavelength of 545) or a pure green or light green (thus purity) and whether it appear bright or dim.
####Theory of Vision
There are two theories that surround color vision, we have the trichromatic theory and the opponent theory. In the trichromatic theory we look at the three main cells in the retina responsible for color vision which are known as cones. These cones have pigments within them that makes then more sensitive to a particular wavelength which are red, blue and green. So what happens is that the mixing of these pigments in the three cones result in our ability to see all different types of colors as stipulated by Thomas Young's Theory. The Opponent Theory, tries to account for some color perception that the trichromatic theory is not able to explain and it says that the three cones responds to contrary colors or otherwise known as opposing pairs and that these two cannot be interpreted at a go. These are blue and yellow, red and green and black and white. These two are direct opposites and one cannot be seen in the other in anyway. Activating one inhibits the other and accounts for the complimentary after image effect.
There is a beauty about seeing in color and the brain's interpretation or perception and thus is color constancy. When you take a picture with a camera based on the lighting of the environment, color of the images changes even with slight variations but the eye does not do this, once we perceive an object to have a particular color it does not change with slight variations in wavelength.
Seeing in color is a beautiful thing and whiles it has many positive effect to us lots of research is still been done to understand the various mechanism surrounding it. The next time you appreciate a beautiful scenery, remember that it is the doing of some pigments in the eye and appreciate the complexities of nature and the human evolution
Steven Schwartz. Visual Percetion, A Clinical Orientation. 5 th ed. McGraw-Hill Education; 2017. ISBN-13: 978-1259585012.
Abney WW. Researches in Color Vision and the Trichromatic Theory. London, UK: Longmans, Green; 1913
https://psyc.ucalgary.ca/PACE/VA-Lab/colourperceptionweb/theories.htm
