The black eyeball side of the eye mostly refers to the corneal rim, if the corneal rim appears white lumps are mostly caused by blepharospasm, pterygium, corneal dermatomas and so on. 1. Blepharospasm: Blepharospasm refers to a triangular elevated plaque in the conjunctiva close to the corneal limbus in the blepharospasm region, which usually does not affect the patient’s vision, but the patient may have a foreign body sensation in the eye. 2. Pterygium: If the patient is exposed to sunlight, sand, smoke and other polluted environments for a long time, and the eyes are exposed to ultraviolet rays, pterygium can be caused, which is mainly manifested as the invasion of the bulbar conjunctiva in the blepharosphenoid region and the fibrovascular tissue under it to the cornea, mostly in the form of triangular elevation. 3. Corneal dermatoma: Corneal dermatoma is a congenital anomaly resembling a tumor, which has the appearance of skin-like color and is mostly located at the corneal limbus below the temporal region. It is recommended that patients with white bumps on the corneal limbus should seek prompt medical attention to evaluate their condition and follow the doctor’s instructions for treatment.