Darkening of the inner side of the patient’s eyes may be caused by conjunctival nevus pigmentosus or scleral staphyloma. Conjunctival nevus pigmentosus is usually caused by congenital developmental abnormality, there is abnormal pigment deposition in conjunctival tissues, which can form black plaques, usually it will not jeopardize the health of the eyes, and it will not affect the patient’s vision. If it affects the appearance, patients can remove it through surgery. If the pigmented nevus increases significantly within a short period of time, or even breaks down and bleeds, it should be suspected of malignant transformation and needs to be removed as soon as possible. Scleral staphyloma, on the other hand, is usually formed due to the bulging of the local sclera that cannot tolerate the pressure inside the eye after thinning. Because of the local thinning of the wall of the eyeball, it will transmit the color of the inner choroid of the eyeball, and thus looks dark. It is recommended that patients with inner darkening of the eye should consult the hospital in a timely manner to assess their condition and undergo treatment under the guidance of a doctor.