The yellowing of the lower half of the eye may be caused by physiological and pathological reasons, such as blepharospasm, infection and so on. 1. Physiological reasons: it may be with the growth of age, external wind and sand stimulation, etc., resulting in gradual pigmentation, the phenomenon of yellowing of the lower half of the sclera, generally do not need special treatment. 2. Pathological causes: (1) Blepharoplakia: long-term exposure of the bulbar conjunctiva in the eyelid fissure department, which is stimulated by the outside world, such as ultraviolet rays or chemical substances, causes yellow plaque. (2) Infection: wearing contact lenses for a long time and not doing a good job of eye cleaning and hygiene, so that there are bacteria and other infections in the eye, leading to inflammation and stimulation of the lower half of the sclera to appear yellowing. Appearance of yellowing in the lower half of the eye, and accompanied by other discomforts, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, to clarify the cause, and carry out targeted treatment.