Colour perception

When we talk about sight, we need to keep in mind (and of course in sight) the fact that eyes are “light collectors“. It means that we perceive an object when light is diffused off of it into our eyes.

The rays of light which reach our eyes when we see something are not coloured themselves, however. The perception of colour happens in the eyes and the brain during the process of sight. In the retinas of the eyes, there are three types of sensory cells, the so-called cones. Each cone is activated by a different part of light. One type of cone is activated above all by blue parts of light, another one by green and the third one by red light. When the right light hits the according type of cone, the cone sends a signal to the brain. When two or all three sensory cells are activated at the same time, the brain calculates a specific mixed colour. Depending on how intensively the three types of cones are activated, different colours are perceived.

The retina spreads over the inner back surface of the eye. Countless information about the character of light are processed in the brain, so to visualize the entire field of view.