Because there is no iris tissue in the pupil area, and the lens, vitreous body and fundus tissue after the pupil, there is no obvious light reflection, so the normal observation of the pupil color is black, because there is no reflection inside. If the color of the pupil becomes lighter, it suggests that the lens or the vitreous body and the fundus tissue after the pupil, because of some diseases have a reflective manifestation, from the cause of this change in the etiology, the most common type of cause is due to the crystalline causes, that is, the production of cataracts. Cataracts cause the crystalline lens to become cloudy and reflective, resulting in a whitish coloration of the pupil area, a phenomenon known clinically as albinism. This phenomenon is clinically known as leukocoria. This color change of the pupil caused by cataract may be seen in infants and young children with congenital cataracts, or in middle-aged and elderly people with senile cataracts, and in young adults due to trauma or radiation, cataracts may also occur, which is a very important cause of the disease. In infants and young children, there is another type of cataract, which may be caused by neoplastic diseases of the retinal tissue at the bottom of the eye, which may lead to the observation of reflections from the bottom of the eye in the pupil area, i.e., infantile leukoplakia, which is commonly seen in infants and young children, such as retinoblastoma.