When the eye looks like a layer of white fog, it is mainly due to the following reasons: first, it is caused by corneal epithelial edema, usually caused by keratitis, severe dry eye and glaucoma resulting in elevated intraocular pressure, all easily triggered by corneal edema, so that the corneal transparency is reduced, forming a hairy glass-like appearance, so that things look like a layer of white fog; second, it is caused by corneal dystrophy, whether epithelial type Second, it is caused by corneal dystrophy, whether it is epithelial, stromal or endothelial corneal dystrophy, it will form tiny white foci on the cornea, making the eye look like a layer of fog; third, it is caused by iridocyclitis, which causes the atrial fluid inside the patient’s eye to become cloudy and less transparent, making it look like a layer of fog; fourth, it is caused by cataract, which causes the lens inside the eye of cataract patients to become The lens inside the eye of cataract patients will become cloudy and less transparent, which will also cause the above symptoms.