Black patches in children’s eyes may be caused by foreign bodies in the eye, pigmentation spots or pigmented nevi. 1. Foreign body in the eye: if children are not careful when playing, foreign body enters into the eye surface, such as iron filings, gravel, etc., black spots in the eyes of children may appear. 2. Pigmented spots: pigmented spots can occur in various parts of the patient’s conjunctiva, the surface is smooth without blood vessels, when observed, black patches can be seen in the child’s eyes, and the conjunctival nevus of pigmentation will not continue to grow in most cases. 3. Nevus pigmentosus: Nevus pigmentosus may appear on the sclera and conjunctiva of the child, resulting in the appearance of black patches in the eyes of the patient, this kind of nevus pigmentosus is usually caused by congenital factors, and will not cause obvious effects on the eyesight and the structural function of the eyeball. It is recommended that patients with dark patches in the eyes and other discomforts should consult a doctor promptly to evaluate their condition and follow the doctor’s instructions for treatment.