How do we perceive different colors of light?

We perceive different colors of light through the way our eyes and brain interpret light’s wavelength. Here’s the process step-by-step:

1. Light enters the eye
   • Light from an object passes through the cornea and lens, which focus it onto the retina at the back of the eye.
2. Detection by photoreceptor cells
   • The retina contains two main types of light-sensitive cells:
     • Rods – very sensitive to brightness but not to color (used in dim light).
     • Cones – responsible for color vision; work best in bright light.
   • Cones come in three types:
     • S-cones (short wavelength) – most sensitive to blue light.
     • M-cones (medium wavelength) – most sensitive to green light.
     • L-cones (long wavelength) – most sensitive to red light.
3. Color processing in the brain
   • When light hits the cones, they produce electrical signals based on how strongly they respond to that wavelength.
   • The optic nerve sends these signals to the brain’s visual cortex, which compares the cone responses to determine the exact color.
4. Perception of mixtures
   • Pure wavelengths produce spectral colors (red, green, blue, etc.).
   • Mixtures of wavelengths (like sunlight or a TV screen’s pixels) create the perception of intermediate colors.