The perception of color in the eye is due to the presence of special cells called cone cells. These cells are located in the retina, which is the light-sensitive tissue at the back of the eye. Cone cells are responsible for detecting and responding to different wavelengths of light, which are then interpreted by the brain as different colors.
Blue and yellow are considered complementary colors because they are located at opposite ends of the visible light spectrum. Blue light has a shorter wavelength and higher frequency, while yellow light has a longer wavelength and lower frequency. When these two colors are mixed together, they cancel out each other's wavelengths, resulting in white light.
The cone cells responsible for detecting blue and yellow light have different levels of sensitivity to these colors. Blue light is detected by the S-cones, which are most sensitive to shorter wavelengths of light. Yellow light is detected by the L-cones, which are most sensitive to longer wavelengths. This difference in sensitivity allows the brain to distinguish between the two colors.
Colorblind individuals may have difficulty distinguishing between blue and yellow, depending on the type and severity of their color vision deficiency. In most cases, blue-yellow color blindness is caused by a lack of functioning S-cones or L-cones, resulting in a limited ability to perceive these colors.
When blue and yellow light are combined in the eye, they activate both the S-cones and L-cones simultaneously. This creates a perception of white light, rather than a distinct blue or yellow color. This is why when we see objects that appear blue or yellow, they are actually reflecting or emitting light in those specific wavelengths.