White spots on the eyes are usually caused by the following reasons: First, white spots on the surface of the black eye are usually caused by keratitis, corneal leukoplakia, etc. Second, white spots appear inside the eyeball, usually due to cataract and other reasons. Third, white spots appear at the edge of the eyelid, usually due to the obstruction of the opening of the meibomian gland and the accumulation of secretions. Fourth, white spots appear on the surface of the eye skin, usually due to miliaria or syringoma.