The pupil has a black spot, usually due to the following reasons: 1, due to corneal foreign bodies, such as iron filings, sand, etc. If the eyes embedded in the cornea, will lead to black spots on the black eye, but also a strong eye stinging, foreign body sensation, tearing, afraid of the light, eye red and other symptoms, you need to take out the foreign body in a timely manner. 2, due to the iris nevus pigmentation caused by the iris itself is rich in pigment, the local iris cells if there are abnormalities in pigment metabolism, there will be a black spot. The iris itself is rich in pigment, and if the local iris cells have abnormal pigment metabolism, black spots will appear, if the condition is stable, usually do not need to be treated. 3, is due to iridocorneal endothelial syndrome, the patient’s iris will atrophy and thus form a hole, forming a black patchy appearance, and there may also be secondary glaucoma, endothelial function of the cornea is not compensated for the complication.