Sudden vision loss and blurred vision are mainly related to hemorrhage or ischemia of blood vessels in the eye. Transient ischemia is common among young people, a transient ischemia that recovers after 1-2 minutes, which doesn’t require much treatment, just try to avoid getting up and sitting down as much as possible. The most common cause of sudden vision loss in middle-aged people is venous obstruction, which causes hemorrhage in the fundus of the eye and macular edema, leading to sudden vision loss. Diabetic retinopathy is common in the elderly and can also cause hemorrhages in the fundus or even vitreous hemorrhage, causing sudden vision loss. Ischemic optic neuropathy in the elderly can also cause vision loss. Central venous obstruction is an obstruction of arterial vessels or venous vessels, and the ischemia it causes can also lead to sudden loss of vision. Therefore, if you have a sudden loss of vision, it is important to go to the hospital for an examination to rule out fundus lesions. Some fundus lesions may require laser treatment and some may require surgery.