Final answer:
Normal-sighted individuals are classified as trichromats because they have three types of cones that are sensitive to red, green, and blue light, allowing them full color vision according to the trichromatic theory of color vision.
Step-by-step explanation:
In the context of color vision among normal-sighted individuals, normal people are classified as trichromats. This is because they have three types of cones in their eyes, with each type being maximally sensitive to a different wavelength of light. These cones are referred to as S cones (sensitive to short wavelengths), M cones (sensitive to medium wavelengths), and L cones (sensitive to long wavelengths). The trichromatic theory of color vision explains that all colors in the spectrum can be perceived by combining the inputs from these three types of cone cells, which respond to red, green, and blue light, respectively.