Theories of vision explain how we perceive the world through sight. One prominent theory is the trichromatic theory, which suggests that our eyes have three types of color receptors sensitive to red, green, and blue light. These receptors work together to create the full spectrum of colors we see. Another important theory is the opponent-process theory, which posits that we perceive colors in terms of opposing pairs: red-green, blue-yellow, and black-white. This means that when one color in a pair is stimulated, the other is inhibited, helping us understand how we perceive contrasting colors in our environment.