Pain in the eyes when tears occur is mainly due to the following causes: 1. Due to blepharitis, especially canthal blepharitis and ulcerative blepharitis. As a result of skin breakdown and inflammatory lesions in the marginal area of the eyelids, the tears contain a large amount of inorganic salts, which causes reflex pain after the tears stimulate the lesions. 2. due to eczema in the eyelid area, which is most likely to occur in the outer corner of the eye and is related to long-term tear soaking. The pain is caused by local skin breakdown, when the broken skin comes into contact with the inorganic salts in the tear fluid. 3. It is caused by keratitis and corneal epithelial defects, etc., and usually occurs after trauma to the eye. Tears flushing the lesion during tearing and frequent blinking caused by tearing can cause irritation to the lesion causing eye pain.