Color blindness or color vision

Color vision

Color vision is the capacity of an organism or machine to distinguish objects based on the wavelengths of the light they reflect, emit, or transmit...

 deficiency is the inability or decreased ability to see color

Color

Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...

, or perceive color differences, under lighting conditions when color vision is not normally impaired. "Color blind" is a term of art; there is no actual blindness but there is a fault in the development of either or both sets of retinal cones

Retina

The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

 that perceive color in light and transmit that information to the optic nerve.