Excess tearing may cause a sensation of watery eyes or result in tears falling down the cheek. Other symptoms, such as eye irritation or pain, may be present depending on the cause.
Most tears are produced in the tear (lacrimal) glands located above the outer part of the upper eyelid. Tears run across the eye and drain through small openings at the inner corners of the eyelids near the nose (the upper and lower puncta) into short channels (the canaliculi). They then run into the tear sac and through the nasolacrimal duct into the nose. Blockage anywhere along the tear drainage pathway can lead to a watery eye. Blockage also predisposes to infection of the tear sac (dacryocystitis Dacryocystitis Dacryocystitis is infection of the tear (lacrimal) sac usually due to a blockage in the tear (nasolacrimal) duct. The tear sac is a small chamber into which tears drain. The usual cause of dacryocystitis... read more ). Such infection can sometimes spread to tissues around the eye (periorbital cellulitis Preseptal Cellulitis Preseptal cellulitis is infection of the eyelid and of the skin and tissues around the front of the eye. (See also Introduction to Eye Socket Disorders.) Both preseptal cellulitis and orbital... read more ).
Where Tears Come From
Common causes of watery eyes are
Upper respiratory infections
Allergies that affect the nose (allergic rhinitis), eyes (allergic conjunctivitis Allergic Conjunctivitis Allergic conjunctivitis is inflammation of the conjunctiva caused by an allergic reaction. Allergic reactions caused by, for example, airborne allergens, may inflame the conjunctiva. Redness... read more ), or both
Other causes include
Dry eyes Dry Eyes A number of other symptoms and problems can affect the eyes, including changes in the appearance of the eyes, color blindness, dry eyes, glare and halos, impaired depth perception, itchy eyes... read more (the dry surface of the eye becomes irritated, the tear glands produce "reflex" tears, and thus, surprisingly, dry eyes can cause watery eyes)
Inwardly turned eyelid (entropion) or eyelashes that rub against the eyeball (trichiasis Trichiasis Trichiasis is misalignment of eyelashes, which rub against the eyeball, in a person who does not have entropion. Trichiasis develops most commonly some time after chronic blepharitis (inflammation... read more )
An outwardly turned eyelid (ectropion Entropion and Ectropion Entropion is a condition in which the eyelid is turned inward (inverted), causing the eyelashes to rub against the eyeball. Ectropion is a condition in which the eyelid is turned outward (everted)... read more ) that moves the punctum away from its normal position next to the eyeball so that it cannot drain away tears
Age-related narrowing of the tear ducts, called acquired dacryostenosis Acquired dacryostenosis Dacryostenosis is narrowing of the nasolacrimal duct, which drains tears away from the eye. Dacryostenosis can be present from birth (congenital) or develop after birth (acquired). Either type... read more
Any disorder that irritates the cornea (the clear layer in front of the iris and pupil) can increase tear production. However, most people with corneal disorders Introduction to Corneal Disorders The cornea is the clear layer in front of the iris and pupil. It protects the iris and lens and helps focus light on the retina. It is composed of cells, protein, and fluid. The cornea looks... read more that cause watery eyes (such as a corneal scratch or sore, a foreign object in the eye, or inflammation of the cornea) have significant pain, redness, and/or sensitivity to light, which are the usual reasons they seek medical care.
Not every case of watery eyes requires evaluation by a doctor. The following information can help people decide when a doctor's evaluation is needed and help them know what to expect during the evaluation.
In people with watery eyes, certain symptoms and characteristics are cause for concern. They include
Repeated, unexplained episodes of red watery eyes
A hard mass in or near the tear duct
When to see a doctor
People with warning signs should see a doctor within a week or so. Other people who are bothered by watery eyes should see a doctor when it is convenient, but typically a delay of several weeks is not harmful.
What the doctor does
Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests the cause of the watery eyes and the tests that may need to be done (see table Some Causes and Features of Watery Eyes Some Causes and Features of Watery Eyes ).
Doctors ask whether the person has
Itching, a runny nose, or sneezing (especially after being exposed to a potential allergen)
Eye irritation, redness, or pain
Pain or discomfort with swelling or redness near the inner corner of the eye
Other symptoms (for example, headache, cough, fever, or rash)
Had injuries, infections, burns, radiation therapy, or surgical procedures involving the eyes, nose, or sinuses
Taken a drug that may cause watery eyes (such as chemotherapy drugs or eye drops containing echothiophate, epinephrine, or pilocarpine)
Doctors then do a physical examination. The physical examination focuses on the face, particularly the eyes and nose. Doctors look for tears running down the cheek, which suggests blockage along the tear drainage pathway. However, signs of a specific cause may be absent. Doctors examine the eyelids, the puncta, and the area at the inner corners of the eyes. They also examine the surface of the eye with a slit lamp What Is a Slit Lamp? to examine the eye under high magnification. The nose is examined for congestion, blockages, pus, discharge, and bleeding.
Doctors can usually determine the cause based on the results of the history and physical examination. Testing is often unnecessary. If testing is needed, the person usually is referred to an ophthalmologist (a medical doctor who specializes in the evaluation and treatment—surgical and nonsurgical—of eye disorders).
Some tests are done in the ophthalmologist's office. Doctors may insert a small probe into the punctum and sometimes the canaliculus to try to detect blockage. They may also gently flush fluid through the canaliculus to see whether the fluid drains into the nose as it should.
Imaging tests and procedures (imaging of the tear ducts, computed tomography [CT] of the face and orbits, or examination of the inside of the nose with a flexible viewing tube [nasal endoscopy]) are sometimes done.
Underlying disorders are treated. For example, doctors may give a nasal corticosteroid if allergic rhinitis is the cause.
Doctors sometimes recommend the use of artificial tears to decrease watery eyes when dry eyes or eye surface irritation is the cause.
In infants with blocked tear ducts Dacryostenosis Dacryostenosis is narrowing of the nasolacrimal duct, which drains tears away from the eye. Dacryostenosis can be present from birth (congenital) or develop after birth (acquired). Either type... read more , the blockage often resolves without treatment as the infant grows. Until the infant is about 1 year old, doctors often suggest that parents manually compress the tear sac 4 or 5 times per day to help relieve the obstruction. If the blockage is not relieved by the time the infant is about 1 year old, doctors may do a procedure to open the ducts. The infant is given a general anesthetic, and the doctor inserts a small probe into the tear duct to break through the blockage.
In children with blocked tear ducts, doctors may first try probing the tear duct. If blockage persists, doctors may need to insert a small plastic tube through the tear duct for a few months to keep a drainage pathway open.
In adults with blocked tear ducts, doctors first try different methods to treat the underlying disorder. If these methods do not work, doctors may have to do surgery to make a new drainage pathway for tears.
Essentials for Older People
As people age, the tear ducts often narrow (acquired dacryostenosis Acquired dacryostenosis Dacryostenosis is narrowing of the nasolacrimal duct, which drains tears away from the eye. Dacryostenosis can be present from birth (congenital) or develop after birth (acquired). Either type... read more ). Such narrowing is a common cause of unexplained watery eyes in older people. However, complete blockage of the tear duct is also possible. Rarely, a tumor of a tear sac is the cause.
Common causes of tearing include allergies, dry eyes, inward or outward turning of the eyelids, as well as infection, narrowing, or blockage of the tear drainage pathway.
Testing, if necessary, can often be done in an ophthalmologist's office.
Other testing, such as dacryoscintigraphy or dacryocystography (imaging tests of the tear ducts) or computed tomography, is necessary when in-office tests do not reveal the cause or doctors suspect a tumor.