Swollen eyes mostly refers to swelling of the eyes, which may be caused by visual fatigue, conjunctivitis, eye allergy, renal insufficiency and so on. 1. Visual fatigue: Patients who use their eyes for a long time, stay in a dim or bright light stimulating environment for a long time, or rub their eyes frequently and vigorously, resulting in visual fatigue, patients may have swollen eyes, which can also be accompanied by soreness, dryness and other uncomfortable symptoms. 2. Conjunctivitis: Bacteria, viruses, fungi and other pathogenic microorganisms infect the lid conjunctiva, causing conjunctival inflammatory material exudation, congestion and other inflammatory reactions, patients may experience eye swelling. 3. Eye allergy: patients with allergies can experience conjunctival congestion, swelling, itching and other discomfort when they come into contact with allergens such as hair, dander, pollen, dust and other allergens, which induces allergic reactions. 4. Renal insufficiency: Kidney diseases such as nephritis, nephrotic syndrome and other renal diseases lead to renal dysfunction, sodium retention in the body, patients may experience eye swelling and other discomforts. It is recommended that patients with obvious eye swelling should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.