Color Vision: Brief Summary

Color Vision Theories

• Color perception originates in the retina; early theories developed by observing human vision.
• Two main theories: Trichromatic theory and Opponent-process theory.

Trichromatic Theory

• Proposed by Thomas Young ($1802$) and extended by Hermann von Helmholtz ($1852$).
• States that color perception uses three types of cone receptors in the retina.
• These cones are sensitive to different, but overlapping, ranges of wavelengths (red, blue, green).
• Evidence:
  • Normal vision: Any color can be matched by combining three specific wavelengths.
  • Reasoning: Visual system bases color perception on the relative responses of these three cone systems.
  • Color-deficient vision: Supports the theory; inability to perceive certain colors depends on which of the three cone systems is inoperative (e.g., green cone malfunction makes green indistinguishable from blue and red combinations).