There are several possibilities for eyes to feel a layer of fog: First, the most common is cataract, because the crystal has turned from transparent to cloudy, looking at things feels like there is a layer of fog like blocking, and there is a blurred vision. The initial stage of cataract can be observed regularly, and after the middle stage, cataract removal and IOL implantation can be done; second, viral keratitis, when viral keratitis occurs, the cornea can appear diffuse dotted circular clouding, and the patient will feel like there is a layer of fog like the vision is unclear, antiviral treatment is needed, ganciclovir eye drops are given four times a day, and ganciclovir eye gel is applied at night before going to bed; third, iris ciliary When iridocyclitis occurs, especially in acute iridocyclitis, fine deposits appear behind the cornea and the anterior chamber becomes cloudy, so you can see things as if there is a layer of fog. It is necessary to dilate the pupil, relax the ciliary muscle and rest, and order flumetron eye drops every two hours to promote the absorption of the cloudiness. If there are systemic diseases such as rheumatism or rheumatoid diseases, treat them accordingly.