The surface of the human white eye is covered with a thin, transparent layer called the conjunctiva. Below the conjunctiva is the white sclera. Yellowing of the eyes generally refers to yellowing or hyperpigmentation of the conjunctiva or sclera. Yellowing of the eyes can also be classified as physiological or pathological. As the old saying goes, “As people age, their eyes may turn yellow as they get older. The function of the eye gradually declines, the conjunctival transparency decreases, and the sclera becomes cloudy and yellow due to the accumulation of lipofuscin deposits and pigmentation. Pathological scleral yellowing has more causes, such as the accumulation of urinary toxins in the blood of patients with uremia, and these toxic substances can lead to gray-white patches (metastatic calcium deposits) in the bulbar conjunctiva and/or corneal limbus. The sclera may also turn yellow in patients with liver disease with impaired liver function and biliary stasis or in those who have developed jaundice. Some conjunctival masses such as pterygium and blepharospasm can also cause yellowing of the conjunctiva. In newborns, increased serum bilirubin can cause physiological or pathological jaundice, and the skin, mucous membranes, sclera, and other tissues of the body can become yellow, presenting a yellowish appearance of the eyes. If the eyes are yellow due to lesions in other tissues, it is often necessary to treat other systemic diseases first. In summary, if the yellowing of the eyes is physiological, no treatment is needed, but if it is pathological, active treatment is required.