Sudden blurring of vision may be caused by trauma, glaucoma, hypoglycemia and optic neuritis. 1. Trauma: If the eye is traumatized, it may lead to sudden blurring of vision and sudden loss of vision. 2. Glaucoma: If the patient is accompanied by eye swelling and discomfort, acute glaucoma cannot be ruled out as the cause. Glaucoma patients with elevated intraocular pressure, compression of the optic nerve at the bottom of the eye, may cause patients with vision loss, blurred vision. 3. Hypoglycemia: When hypoglycemia occurs, the brain can not get enough energy supply, which may cause the patient’s eyes to suddenly blur, and may be accompanied by weakness, panic and other uncomfortable symptoms. 4. Optic neuritis: optic neuritis is an emergency in ophthalmology, patients can show that the eyeball rotation pain at the same time, eye vision suddenly blurred sharp decline, serious cases can only see the black shadow in front of the eyes, vision loss is very serious. 5. Other: central retinal artery obstruction, vitreous hemorrhage and other diseases may also appear in patients with sudden vision loss, blurred vision and other symptoms. It is recommended that patients with sudden vision loss should consult a hospital in time to assess their condition and undergo treatment under the guidance of a professional doctor.