Causes
Watery eyes occur when there is excess tear production or poor tear drainage.
The most common causes of tearing are -
Tearing can be caused by increased tear production or decreased tear drainage.
Increased tear production: The most common causes are -
- URI
- Allergic rhinitis
- Allergic conjunctivitis
- Dry eyes (reflex tearing in response to dryness of the ocular surface)
- Trichiasis or misdirection of eyelashes towards the eye
Any disorder causing conjunctival or corneal irritation can increase tear production. These conditions include conjunctivitis, corneal abrasion, corneal ulcer, corneal foreign body and keratitis (inflammation of the cornea). Similarly, primary angle-closure glaucoma and anterior uveitis may cause tearing but are more likely to manifest with other symptoms, such as pain and redness.
Decreased tear drainage:The most common causes are -
- Congenital nasolacrimal duct blockage
- Dacryocystitis or inflammation or infection of the lacrimal sac
- Ectropion or outward turning of eyelid
Tear drainage system obstruction is mostly a congenital malformation. It may be due to strictures, tumors, or foreign bodies in adults. Chronic infection of the tear drainage pathway almost invariably leads to obstruction to tear flow. Ectropion, seen in elderly and in patients of facial palsy, causes spilling of the tears and failure of lacrimal pump resulting in watery eyes.
