Too weak to be a soldier. According to the article "Physical Examination Standard for Citizens Recruited" published by the National Recruitment Network, it can be known that those who can distinguish red, green, yellow, blue and purple are qualified. Weak color is also called "abnormal trichromatic vision". Color vision defect. Those who can recognize colors but have low sensitivity are called weak colors. Patients with weak color have poor ability to distinguish colors, and can only see colors when they are saturated; Only when the wavelength difference is large can we distinguish the change of the bright phase. Red weakness (A) and green weakness (B) are common, while blue weakness is extremely rare. Weak red has poor ability to distinguish red; Weak green has poor ability to distinguish green. The patients with weak color are mostly men.