Most blurred vision is caused by eye diseases. Common eye diseases that cause blurred vision are: 1. Transient blurred vision or even loss of vision: This means that vision can return to normal within a short period of time, usually no more than 24 hours. Common eye conditions include: optic disc edema (for a few seconds, usually in both eyes), central retinal artery spasm, and impending central retinal vein occlusion. It can also be seen occasionally in ischemic optic neuropathy and glaucoma, etc. 2, sudden vision loss: 1) common eye diseases not accompanied by eye pain include: retinal artery or vein obstruction, ischemic optic neuropathy, vitreous hemorrhage, retinal detachment, optic neuritis (usually accompanied by eye movement pain), etc. 2) common eye diseases accompanied by eye pain include: acute angle-closure glaucoma, uveitis, corneal inflammation, endophthalmitis, ocular trauma, etc. 3) Common eye diseases with gradual vision loss are: cataract, refractive error (myopia, hyperopia, astigmatism), primary open-angle glaucoma, chronic retinal diseases (such as age-related macular degeneration, idiopathic macular fissure, chronic corneal diseases); optic neuropathy due to poisoning and tumor; hypertension, renal disease, hematological disease, diabetes and other systemic diseases when ocular complications occur, etc. In addition, blurred vision can also occur in transient ischemic attacks; inadequate blood supply to the vertebral basilar artery, postural hypotension, psycho-stimulating blackout, hysteria, overexertion, migraine, sudden changes in blood pressure, acute orbital pressure elevation, and central nervous system lesions.