What Causes Unilateral Tearing and How Can It Be Treated?

Unilateral tearing happens when one eye waters more than usual, which can be bothersome and sometimes confusing. The most common causes include blocked tear ducts, irritation from a foreign object, allergies, infections, and structural problems around the eye. Many people notice signs of excessive eye watering, such as constant tears running down the cheek, blurred vision, or a sensation of something in the eye.

Some people may not know why just one eye is affected. This type of eye issue should not be ignored, as figuring out the reason is an important step toward relief. Taking a quick quiz for causes can help narrow possible reasons and guide the next steps for treatment.

Key Takeaways

• Unilateral tearing can be caused by blockages, infections, or irritation.
• Identifying the main cause helps decide on the best treatment.
• Quick tools and simple checks can help spot the signs and address problems early.

Primary Causes of Unilateral Tearing

Unilateral tearing, also called epiphora, often comes from mechanical problems, blockages, or surface irritation affecting only one eye. Often, the problem is isolated to the structures that handle tear drainage or stability on that side.

Obstruction of the Lacrimal Drainage System

A blocked lacrimal drainage system is the most frequent single-eye cause of tearing. The system includes the puncta, canaliculi, lacrimal sac, and nasolacrimal duct. If any part of this pathway becomes narrowed or blocked, tears cannot drain properly. Common conditions include nasolacrimal duct obstruction, canaliculitis (infection of the canaliculi), and dacryocystitis (infection of the lacrimal sac).

Adults often develop obstructions due to inflammation, infection, injuries, or age-related narrowing. In some cases, children are born with a congenital blockage. Signs include constant tearing, mild discomfort, or thick discharge. Simple blockages may often be diagnosed by gently pressing over the lacrimal sac and watching for reflux.

Treatment depends on the cause. Frequent treatments include warm compresses, massage, or surgical procedures to open or bypass the blockage. Prompt care can prevent infection and protect the eye's surface.

Eyelid Malposition and Related Disorders

Eyelid malpositions such as ectropion (where the lid turns outward) and entropion (where it turns inward) disrupt normal tear drainage. These changes often result from aging, trauma, or previous eyelid surgery. If the lower eyelid droops, the puncta may not align with the tear film, leading to an overflow of tears.

Disorders like eyelid laxity or scarring, as well as trichiasis (misdirected lashes), may also trigger excessive tearing or irritation. These problems cause improper spread of tears or interfere with the tear "pump" system during blinking.

Surgical repair is often needed to restore eyelid position. Procedures can tighten the lid or realign the puncta. In mild cases, taping the eyelid may sometimes give short-term relief. Restoring normal anatomy usually brings noticeable improvement in symptoms.

Ocular Surface and Tear Production Abnormalities

Disorders of the ocular surface or tear production can lead to reflex tearing. Paradoxically, dry eye is a common cause. In this condition, tear production is unstable, and the eye responds to dryness and irritation by overproducing tears that do not drain well.

Irritation caused by blepharitis (eyelid margin inflammation), allergy, corneal abrasion, or infection can also stimulate excess tearing. Sometimes, reflex tearing is secondary to problems with the conjunctiva or cornea not related to the drainage system.

Treatment often involves addressing dryness, inflammation, or other triggers with artificial tears, eyelid hygiene, or anti-inflammatory drops. Occasionally, managing lid disease or allergies helps restore tear stability and comfort.

Neoplastic and Rare Causes

Rarely, tumors or growths within the lacrimal system, eyelid, or nearby tissues can cause unilateral tearing. Both benign and cancerous tumors may physically block the nasolacrimal duct or press on the lacrimal sac. Conditions like sarcoidosis, which is an inflammatory disease, may also affect the drainage pathway.

Signs that suggest a neoplastic or rare cause include a mass near the inner corner of the eye, bloody discharge, pain, or sudden change in tearing pattern. These cases usually require imaging exams and referral to a specialist. Treatment depends on the type and location of the lesion and may include surgical removal, biopsy, or medication. Prompt detection can help protect vision and eye health.

Diagnosis and Treatment Options for Unilateral Tearing

Unilateral tearing happens when one eye produces too many tears or cannot drain them well. Finding the exact cause of the tearing helps guide what steps to take for relief and long-term care.

Clinical Evaluation and Diagnostic Approach

Doctors begin with a detailed history and eye exam. They check for swollen or red eyelids, tender areas near the nose, or crusting, which can point to conditions like blepharitis or dacryocystitis. They may press over the lacrimal sac to see if discharge leaks from the puncta.

A careful look at the eyelids, puncta, and tear film helps spot eyelid disorders or blockage. Fluorescein dye or irrigation can show if the nasolacrimal duct is working well. Imaging, such as dacryocystography or CT scans, may be used for complex or unclear cases, such as tumors or granulomatous disease like sarcoidosis.

Doctors also consider rare causes like canaliculitis or canalicular obstruction, which may show as chronic redness or swelling at the inner corner of the eye.

Medical and Surgical Treatments

Mild cases or those related to eyelid inflammation, such as blepharitis, often start with warm compresses and lid cleaning. Antibiotic or steroid drops may help if there is infection or significant inflammation.

For blockages within the lacrimal system, especially the nasolacrimal duct, doctors may try irrigation or stenting. If these fail, a dacryocystorhinostomy is often performed. This surgery creates a new passage for tears to drain from the lacrimal sac into the nose.

Infections like dacryocystitis need oral or intravenous antibiotics before considering procedures. Canaliculitis is usually managed with topical antibiotics or, in some cases, surgery to remove affected tissue.

Long-Term Management and Prognosis

After surgery, tear drainage usually improves, but regular follow-up is important. Patients may need to continue eyelid hygiene or use eyedrops for blepharitis to prevent future problems.

Chronic or recurring conditions, such as those caused by sarcoidosis, may need involvement from other specialists and medications to control inflammation. Regular monitoring checks for signs of new blockages or infections.

Most people recover well, but a small number may have ongoing issues and benefit from repeat treatments or long-term therapy. Early diagnosis helps prevent complications and improves comfort.

Conclusion

Unilateral tearing can happen for a few reasons such as a blocked tear duct, eye irritation, or eyelid problems. Sometimes the cause is simple, but other times it may need a closer look by a medical professional.

Treatment depends on the cause. This might include using eye drops, applying warm compresses, or even a minor procedure.

It helps to keep the area clean, avoid rubbing the eyes, and note if any new symptoms appear. Taking quick action can often prevent more discomfort later on.