Abnormal color vision

Color vision is a basic and important component of visual function, and is a special sensory function of human retinal cone cells. Normal human vision can recognize visible light with a wavelength of 380-760 um, and consists of 7 colors: purple, blue, cyan, green, yellow, orange, and red. Color vision disorders include color blindness and color weakness. Color blindness refers to the disappearance of color discrimination, and color weakness refers to the decrease in color discrimination. People with abnormal color vision are limited in their career choices. If engaged in transportation, smelting, fine arts, chemicals, weaving and dyeing, medicine, etc., all must have normal color vision. Therefore, the color vision test has been used as a routine item of physical examination.