Watery Eyes: Main Causes of Tearing

A tear on the cheek without reason is not always about emotions. The eye is constantly moistened, and when the balance between tear production and drainage is disrupted, fluid overflows over the edge of the eyelid. We explain what causes this and when it is time to see an ophthalmologist.

Why eyes water: how the lacrimal system works

The lacrimal glands produce fluid constantly, not only when we cry. Part evaporates from the cornea and sclera, part drains through the lacrimal punctum in the inner corner of the eye into the nasolacrimal duct and further into the nose. Normally, production and drainage are balanced with adjustment for evaporation.

Tearing, or lacrimatio, is the overflow of lacrimal fluid from the conjunctival sac through the edges of the eyelids onto the skin of the face. It can be physiological or pathological. If tears flow for a long time and constantly, doctors speak of epiphora, or dacryorrhea.

What makes the eye water: common causes of tearing

There are two mechanisms: tears are produced more than needed, or they are drained worse with normal production.

A separate story is dry eye. When the tear film dries out, the eye reflexively increases tear production, and the person comes with the complaint "eyes are very watery." At-risk groups include:

• age over 50 years;
• contact lenses and long work at a screen without breaks;
• dry, dusty or windy air, air conditioners and heaters, tobacco smoke, alcohol;
• some medications, such as antidepressants or blood pressure drugs;
• blepharitis, Sjögren's syndrome, lupus erythematosus.

Another group of causes is irritation and inflammation of the eye: abnormal eyelash growth (trichiasis), eyelid inversion (entropion), allergic reactions. Here tearing is also protective.

Watery and crusty eyes: possible infectious causes

With inflammation of the conjunctiva of infectious or allergic origin, tear production reflexively increases.

A separate scenario is blockage of the lacrimal duct, which itself increases the risk of infections. Stagnation of tears in the lacrimal sac can lead to dacryocystitis: swelling appears to the side of the nose, near the corner of the eye. In infants, a warning sign is pus in the eyes or stuck eyelids: this may be conjunctivitis.

Why the eye waters constantly: impaired tear drainage

Obstruction of the lacrimal duct—partial or complete—means that tears do not drain into the nose, accumulate, and overflow onto the cheek even without crying. In children, the duct may not be fully formed at birth: closed or covered by a thin film. Then tearing is noticeable as early as 2–3 weeks of life, and tears look thicker.

In adults, the duct is damaged by infection, trauma, or tumor. Other causes include age-related changes, conjunctivochalasis, ectropion and entropion, closure of the lacrimal punctum, dacryocystitis, rhinitis, consequences of facial bone fractures and eyelid injuries. In infants, the duct most often opens on its own by one year.

How the cause of tearing is identified

Diagnosis begins with conversation and examination: how the eyelid is positioned, whether there are crusts, where the tear goes. Often additional tests are not needed. If obstruction is suspected, a fluorescein test is done—the dye shows how tears drain. X-ray examination of the lacrimal duct is rarely performed.

A quick self-check: are both eyes watery or one; do tears appear outdoors and in air conditioning or also flow in a calm environment; are there crusts and stuck eyelids in the morning; has the shape of the eyelid changed visually. These observations help the doctor when taking a history.

When tearing requires a visit to the doctor

See an ophthalmologist if tears constantly overflow onto the cheek: the earlier the cause is found, the more successful the treatment. Another reason is tearing if it persists for several weeks, and any change in eyelid shape. If the eye hurts and is red, or you wear lenses and the eye has become red, an appointment is needed urgently: infection is possible.

Tearing by itself is not a reason to call an ambulance; 103/112—if vision has changed (wavy lines, flashes, loss of vision), it is painful to look at light, a red eye with severe headache and nausea, the eye is very dark red, there has been an eye injury or a foreign object is stuck in the eye.

This material is for reference: it helps to understand the causes but does not replace a doctor's consultation.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer