Color vision Color vision Color vision is the ability of an organism or machine to distinguish objects based on the wavelengths (or frequencies) of the light they reflect, emit, or transmit. Colors can be measured and quantified in various ways; indeed, a person's perception of colors is a subjective process whereby the brain responds to the stimuli that are produced when incoming light reacts with the several types of cone cells in the eye. In essence, different people see the same illuminated object or light source in different ways. Isaac Newton discovered that white light, after being split into its component colours
Macula of retina distinguish different colors. There is only one type of rod, but the rods are more sensitive than the cones, so in dim light they are the dominant photoreceeptors active, and without information provided by the separate spectral sensitivity of the cones it is impossible to discriminate colors. In the fovea "centralis", cones predominate, and are present at high density. The macula is thus responsible for the central, high-resolution, color vision that is possible in good light; and this kind of vision is impaired if the macula is damaged, for example in macular degeneration. The clinical macula is seen when viewed