Old eye boogers are the result of pathologic discharge from the eyes. There are many causes of pathologic eye discharge. The causes can be initially determined according to the nature and morphology of the ocular discharge:1. The discharge is purulent, and the common causes may be blepharitis, lid abscess, chronic dacryocystitis, acute conjunctivitis, gonococcal conjunctivitis, neonatal ophthalmia, etc.2. The discharge is mucous, and the common causes are chronic conjunctivitis, trachoma, viral conjunctivitis, allergic conjunctivitis, chronic dacryocystitis, etc.3. The discharge is plasmatic, and the common causes are viral conjunctivitis, allergic conjunctivitis, etc.4. The discharge is fibrinous. The common causes are viral conjunctivitis, allergic conjunctivitis, etc. 4, the secretion is fibrous, the common causes are pseudomembranous conjunctivitis, diphtheria conjunctivitis, etc. 5, the secretion is filamentous, the common causes are springtime conjunctivitis, etc. 6, the secretion is frothy, most often due to the blepharoplakic glands are secreting vigorously, vitamin A deficiency, etc. It is recommended that patients first go to the hospital to find out the cause of the increased eye discharge, and timely treatment.