Why do my eyes constantly tear up at the corners?

Excessive tearing from the corners of the eyes may be caused by various factors. Overproduction of tears by the lacrimal gland or blockage of the tear ducts can prevent normal drainage of tears, leading to persistent tearing. Eye conditions such as conjunctivitis, keratitis, and other inflammatory infections, as well as eye strain, inward-growing eyelashes (trichiasis), or irritation from foreign bodies, may also cause tearing. Additionally, certain systemic conditions like colds or rhinitis may indirectly lead to tearing. If excessive tearing persists, prompt medical evaluation is recommended.