Eyes also swell during the daytime while sleeping, usually due to edema caused by localized pressure, but also may be caused by localized infections, underlying diseases, or allergic reactions to edema. 1. Localized compression: can lead to venous blood and lymphatic fluid reflux obstruction, it will cause edema, common in the daytime lying on the table to sleep, or lying in bed for a long time side and prone position to sleep. 2. Localized infections: for example, blepharitis, conjunctivitis, etc., can also cause symptoms of eye swelling, mostly redness, pain or itching. 3. Underlying diseases: such as coronary heart disease, nephritis and other underlying diseases, may also cause patients with swollen eyes. 4. Allergic reaction: it is also the cause of eye swelling after sleeping, especially when sleeping eye contact clothing, bedding attached to the dust, willow, skin debris, cotton wool and other triggered allergic reaction caused by edema, is a relatively common situation. When eye swelling occurs during daytime sleep, patients need to promptly go to the hospital ophthalmology consultation, by the doctor to identify the cause and treatment.