What causes watery eyes?

There are various causes of excessive tearing, primarily categorized into physiological and pathological types. Physiological tearing is commonly triggered by emotional changes, eye strain, or irritation from foreign bodies, and usually does not require special treatment. Pathological tearing, on the other hand, may result from a range of eye conditions, such as lacrimal drainage system disorders (e.g., blocked or narrowed tear ducts), ocular inflammations (e.g., conjunctivitis, keratitis), eyelid laxity, or facial nerve paralysis. These conditions can disrupt the normal secretion and drainage of tears, leading to excessive tearing. Additionally, dry eye syndrome, trachoma, and trichiasis are also common causes. For pathological tearing, timely medical evaluation is recommended, followed by targeted treatment based on the underlying cause.