Swollen eyes in children can usually be caused by drinking too much water before going to bed, allergies, kidney disease and other factors. 1. Drinking too much water before going to bed: If children drink too much water before going to bed, the water in the body can not be discharged from the body in time during sleep, so that the increase of water in the body, there will be the symptom of swollen eyes. 2. Allergy: pollen, dust mites and other factors can cause eye allergies, resulting in swollen eyes, often accompanied by itchy eyes, need to stay away from allergens, if necessary, should also follow the doctor’s instructions for anti-allergy treatment. 3. Kidney disease: chronic kidney disease, glomerulonephritis and other kidney diseases can also lead to eye swelling. Kidney disease after its metabolism of water ability to decline, will lead to the body can not be metabolized water accumulation in the body’s loose tissue, such as eyelids, thus causing eye swelling. When children’s eyes are swollen and cannot be relieved for a long time or accompanied by other eye discomforts, it is recommended to go to the hospital as soon as possible for examination, clarification of the cause of the disease and active treatment.