External canthal dehiscence is a type of blepharitis called canthal blepharitis, which is caused by an infection of the bacterium Moraxella catarrhalis and is often limited to the canthus in both eyes, and is most common in the external canthus, often associated with poor health or vitamin B2 deficiency. Patients may experience itching, foreign body sensation, and a burning sensation in the eyes. The outer canthus and skin may be congested, swollen, and macerated, and the adjacent conjunctiva is often associated with chronic conjunctivitis. You can order levofloxacin eye drops and apply Telbivitol gel antibacterial at the skin three times a day, or you can take vitamin B2 orally to help recovery. At the same time, pay attention to eye cleanliness and hygiene, develop good eye habits, avoid visual fatigue, and avoid spicy and stimulating foods in the diet.