How our eyes see color

Our eyes perceive color through specialized cells called cones located in the retina, the light-sensitive layer at the back of the eye. Here's how the process works:

1. Light enters the eye

Light from the environment enters the eye through the cornea and passes through the lens, which focuses it onto the retina.

2. Cone cells detect different wavelengths of light

The retina contains three types of cone cells, each sensitive to different wavelengths of light:

  • S-cones (short-wavelength) detect blue light.

  • M-cones (medium-wavelength) detect green light.

  • L-cones (long-wavelength) detect red light.

These cone cells respond to light within their specific wavelength range and send signals to the brain through the optic nerve.

3. Combination of signals creates color perception

The brain processes the combination of signals from the three types of cones to create the perception of color. For example:

  • Equal stimulation of all three cones results in the perception of white.

  • A mix of red and green signals produces the perception of yellow.

  • Various combinations of stimulation result in the wide range of colors we see.

4. Role of the brain

The visual cortex in the brain integrates the signals from the cones, interpreting the different combinations to produce the full spectrum of colors we perceive in the world.

People with color blindness often have issues with one or more types of cone cells, which affects their ability to distinguish certain colors.

References

  1. How do we perceive color? - Life Theory. https://lifetheory.com/2023/09/11/how-do-we-perceive-color/

  2. Understanding the Role of Cone Cells in Vision. https://www.primescholars.com/articles/understanding-the-role-of-cone-cells-in-vision-125812.html


Featured image attribution

Photo by Zaksheuskaya from Pexels: https://www.pexels.com/photo/pink-and-purple-wallpaper-1616403/

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