Color blindness means that the patient suffers from a congenital color vision disorder and is unable to distinguish a certain color or various colors in the natural spectrum, while color weakness refers to a poor ability to discriminate colors. Color blindness is divided into total color blindness and partial color blindness, such as green blindness, red blindness, blue-yellow color blindness and so on. Total color blindness belongs to complete cone cell dysfunction, patients are especially afraid of light, like darkness, manifested as day blindness, only light and darkness, but not color, is the most serious one of the color vision disorders. Patients with partial color blindness are unable to distinguish certain colors. Color weakness is divided into total color weakness and partial color weakness such as red weakness, green weakness, blue and yellow weakness. Full color weakness, also known as red-green-blue-yellow weakness, is a less severe form of color vision impairment than full color blindness, and there are usually no abnormalities in vision. Partial color weakness is more common in red-green color weakness. Patients usually have poor perception of red and green, and their ability to discriminate colors is close to normal when the colors are deep, well illuminated and sharp. It is recommended that patients with color blindness or color weakness should seek prompt medical attention and treatment as prescribed by the doctor.