The ability to detect and see different colors is due to the cone photoreceptors that lie in the back of the retina in the eyes that detect the three primary colors of red, blue and yellow. A combination of different wavelengths will alter the amount of red, blue and yellow that is perceived, which creates the perception of different colors. The photoreceptors are responsible for detecting the wavelengths and converting them into a chemical signal, which is then responsible for creating an electric signal in the brain.Continue Reading
Other than cone receptors, the retina also has rod receptors which are responsible for detecting black and white. Generally speaking, rod receptors are turned on during the nighttime while cone receptors are active when there is light.
Not everyone has all three cone receptors. Individuals who are missing a cone receptor are known to have color blindness. In these cases, these individuals cannot detect certain colors. Color blindness is actually fairly common and affects about 9 percent of the population. It is also more prominent in men than in women. To detect color blindness in individuals, most doctors rely on a special test known as the Ishihara test, which basically shows pictures with similar colors that need to be detected by various rods. Those without the rods will not be able to see the details within the picture.Learn more about Colors