Sudden blurring of the right eye, i.e., blurred vision, is the main reason why patients present to the hospital. Visual impairment can be categorized as sudden vision loss or gradual vision loss. Sudden vision loss without pain in the eye is most commonly seen in retinal artery spasm, retinal artery or vein obstruction, ischemic optic neuropathy, and fundopathy, where hemorrhage spreads to the vitreous cavity and causes vitreous hemorrhage. There are also fundopathies such as retinal detachment and optic neuritis, all of which cause sharp blurring of vision but are not painful. If sudden blurring of vision is accompanied by eye pain, common diseases are acute angle-closure glaucoma, uveitis, keratitis, and endophthalmitis. Retrobulbar optic neuritis is sometimes accompanied by eye rotation pain, so sudden blurring of vision in the right eye, it is recommended that patients go to the hospital at the first time for examination, clear diagnosis and then symptomatic treatment.