What is color vision?

Color vision allows us to perceive colors due to the way light interacts with our visual system. Light is a form of electromagnetic radiation that varies in wavelength and frequency. In the human eye, this light is detected by neurons in the retina, which are sensitive to different wavelengths. Those wavelengths correspond to different colors, like red, green, and blue.

The retina contains specialized cells known as photoreceptors, specifically cones, that respond to these varying wavelengths. Humans typically have three types of cones, each sensitive to different light wavelengths — one type primarily responds to red light, another to green, and a third to blue. The nervous system processes the signals from these cones to create our perception of the full color spectrum.

When light hits the receptors in the eye, it's converted into electrical signals sent to the brain. The brain interprets these signals, allowing us to see and differentiate colors. This intricate process involves comparison of how much light is absorbed by each type of cone receptor, effectively interpreting the color composition of the light source and the objects it illuminates 1.