Constant tearing of the eyes may be caused by impingement, conjunctivitis, tear duct obstruction, and may also be related to poor mood. 1. Inverted eyelashes: Inverted eyelashes, because the eyelashes grow backward and irritate the surface tissues of the eye, the patient may experience discomfort such as photophobia, tearing, and a foreign body sensation, which may lead to the symptom of constant tearing. 2. Conjunctivitis: Conjunctivitis is an inflammatory disease that occurs in the conjunctival tissues, the causes include infection, immune lesions, etc. Under the stimulation of inflammation, patients may experience conjunctival congestion, photophobia, tearing and other symptoms. 3. Lacrimal duct obstruction: patients with lacrimal duct obstruction may also experience symptoms such as tearing because of poor tear drainage. 4. Poor mood: patients with poor mood can also experience frequent tearing, such as depression, patients with long-term low mood, there will be frequent tearing. It is recommended that patients with frequent tearing and discomfort should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.