Blurred vision in one eye with a foggy feeling needs to be analyzed in two ways, one is transient blurred vision and the other is persistent blurred vision. Transient blurred vision in one eye is related to physiological factors such as improper sleeping posture and excessive fatigue, while persistent blurred vision in one eye is mostly related to ocular pathology. 1, transient blurred vision 1, improper sleeping posture: mostly seen in ambulatory workers, in the process of sleeping with the head down, unilateral eye compression, poor local blood supply, in the process of opening the eyes after waking up, the compressed eye needs a period of time to recover, in this process there will be transient blurred vision; 2, over fatigue: mostly seen in people who stay up late playing cell phones, in the process of lying on the side, one eye is subject to light source Stimulation, while the other side is often in a closed state, when opened again, there will be a transient blur, feel one eye blurred with a layer of fog in the way. For transient monocular blurred vision, proper rest can relieve it. If this situation persists and is not accompanied by other uncomfortable symptoms, the first thing to consider is whether it is due to myopia, astigmatism and other refractive errors that cause vision loss and blurred vision. If the blurring is caused by a loss of vision in one eye, it is recommended to go to the hospital for an eye examination and prescription lenses; 2. Keratitis: When the cornea is diseased, it usually affects the vision, resulting in blurred eyes that feel like a layer of fog is in the way. The inflammation leads to corneal infiltration, ulceration and blurred vision, usually accompanied by eye pain, photophobia, tearing, eyelid spasm and other eye irritation symptoms. When inflammation leads to corneal dystrophy or defects, temporary blurring with layers of fog blocking one eye may also occur. Clinical treatment of inflammation is based on controlling infection, reducing inflammatory response, promoting ulcer healing and reducing scar formation, and commonly used drugs include voriconazole and tobramycin. 3. Cataract: When there is a change in lens transparency in one eye to form a cataract, the patient’s affected eye will produce a blurred feeling with a layer of fog blocking it. The patient’s vision loss will be more obvious and will be accompanied by refractive changes, visual field defects, glare and other abnormalities. The pathogenesis of cataract is complex and is related to age, genetics, metabolic abnormalities, poisoning, trauma, radiation, etc. Clinical treatment for cataract is mainly surgery. The symptoms of glaucoma are usually not obvious in the early stage, when it develops to a certain degree, patients can have blurred vision, headache, eye swelling and other symptoms. Clinical treatment of glaucoma requires lowering intraocular pressure and protecting visual function, and for patients with indications for surgery, anti-glaucoma surgery can be performed. There are many other causes of blurring in one eye with a layer of fog in the way, such as central retinal artery spasm, retinal artery or vein blockage, ischemic optic neuropathy, vitreous accumulation of blood, retinal detachment, tumor invasion, etc. Therefore, when this condition occurs, the first thing to do is to ensure rest, avoid eye fatigue, and avoid rubbing the eyes locally to avoid aggravating the symptoms. If the symptoms persist or recur, it is recommended to visit the ophthalmology department of a regular hospital in time to clarify the diagnosis and give targeted treatment.