Sudden unilateral blindness is usually caused by blockage of the central retinal artery, optic neuritis, and vitreous hemorrhage. Sudden unilateral blindness is usually caused by more serious eye diseases, such as the following. Central retinal artery blockage is usually caused by a thrombosis or an embolus blocking the interior of the central retinal artery, which results in a sudden, painless loss of vision. Optic neuritis is usually caused by an immune response and results in sudden vision loss, usually in one eye. Vitreous hemorrhage, on the other hand, causes the patient’s vitreous cavity to suddenly fill with a large amount of hemorrhage, which affects the refraction of light and can also cause sudden vision loss in one eye. Sudden unilateral eye blindness, it is recommended to seek timely medical examination and treatment, so as to avoid delaying the condition.