About trichromacy (Trichromatic colour vision)
- According to the trichromatic theory of colour vision, there are three types of cone cells in the retina that are responsible for the perception of colour.
- Cone cells are photoreceptors which means they are able to convert light into an electrical charge through a process called photo-transduction.
- Each of the three types of cone cell responds with a bias towards a favoured range of wavelengths of light within the visible spectrum.
- The L cone receptor is sensitive to the red region of the visible spectrum (biased towards 560 nm).
- The M receptor is sensitive to the green region (biased towards 560 nm).
- The S receptor is sensitive to the blue region (biased towards 420 nm).
- The three types of cone cells work in combination with one another to enable the human eye to respond to all wavelengths of the visible spectrum.
- Some researchers suggest that sensitivity to all wavelengths of the visible spectrum enables us to distinguish between as many as seven million different colours.