The appearance of dark patches in the patient’s eyes may be caused by conjunctival or corneal foreign bodies, conjunctival pigmentation, conjunctival nevus and other reasons. 1. Conjunctival or corneal foreign body: when the conjunctiva or cornea enters a foreign body, a black spot may appear on the patient’s eye, which may also lead to the patient’s conjunctival congestion and foreign body sensation and other uncomfortable symptoms. 2. Conjunctival pigmentation: if the patient’s conjunctiva is polluted by ultraviolet rays and dust for a long period of time, pigmentation may appear, and then pigment spots are formed in the conjunctival layer, and the patient may have black spots on the white of the eyes. 3. Conjunctival nevus: Conjunctival nevus mostly appears on the bulbar conjunctiva near the corneal margin or lid fissure part, usually black, with different pigmentation depths, irregularly rounded, and of different sizes. It is recommended that patients with dark patches in the eyes should consult a doctor in time to evaluate their condition and follow the doctor’s instructions for treatment.