A sinus infection occurs when the air-filled cavities in the skull become inflamed, typically due to a viral or bacterial infection. This inflammation causes mucus buildup and pressure, which most people associate with facial pain and congestion. While the primary symptoms are nasal and facial, eye discomfort often accompanies sinusitis. Eye discharge can indeed occur, but it is usually an indirect consequence of the infection rather than a direct flow of sinus contents into the eye.
Understanding the Sinus-Eye Connection
The anatomical structure of the face links the sinuses and the eyes through a shared drainage pathway. The ethmoid sinuses, located between the eyes, and the maxillary sinuses, positioned beneath the eyes, are separated from the eye sockets only by thin layers of bone. When the mucous lining of these cavities swells during an infection, the pressure and inflammation easily impact the surrounding area.
The nasolacrimal duct, often called the tear duct, drains tears and surface debris from the eye into the nasal cavity. This duct empties near the opening of the maxillary sinus. Swelling of the nasal lining, a hallmark of sinusitis, can cause mucosal tissue to expand. Since the tear duct opening is naturally narrow, this minor swelling can physically compress or plug the duct shut. This blockage prevents the normal flow of tears away from the eye, leading to backup.
Eye Symptoms Caused by Sinus Pressure
The inflammation and pressure generated within the sinus cavities can cause several symptoms around the eyes. Many individuals report a dull ache or throbbing pain that feels located behind the eye. This is often due to the pressure buildup in the ethmoid and sphenoid sinuses, which are positioned deep within the skull near the optic nerves.
This pressure also contributes to visible signs, such as puffiness or swelling of the eyelids and the tissues surrounding the eye. When the nasolacrimal duct is blocked, the most common symptom is excessive tearing, known as epiphora. The tears spill over the eyelid margin because the drainage system is temporarily non-functional.
This constant overflow of tears keeps the eye surface wet, leading to irritation and a perpetually watery appearance. These pressure-related symptoms can fluctuate throughout the day, often worsening when lying down or bending over as gravity shifts the congested fluids.
Distinguishing Discharge: Backup vs. Secondary Infection
Eye discharge associated with a sinus infection generally falls into two categories, each indicating a different underlying cause.
Backup Discharge
The first type is a mild, watery, or slightly sticky discharge that results purely from the blocked drainage system. This discharge is essentially stagnant tears and natural eye secretions that have accumulated at the inner corner of the eye. This backup discharge may appear whitish or clear and often causes the eyelids to stick together slightly upon waking. The eye usually maintains a white appearance, with redness limited only to the inner corner near the blocked duct.
Secondary Bacterial Infection
The second, more concerning type is a thick, yellow, or greenish discharge that crusts heavily and often accompanies diffuse redness across the white of the eye. This purulent discharge indicates a secondary bacterial infection, such as conjunctivitis (pink eye). The stagnant tears and compromised drainage caused by the sinus infection create a favorable environment for bacteria to multiply. Bacteria from the nasal cavity or sinuses can sometimes travel up the nasolacrimal duct, or the infection can be introduced by touching the irritated eye.
When to Seek Medical Evaluation
While most sinus-related eye symptoms resolve once the underlying infection is treated, certain signs require prompt medical attention. Individuals should seek evaluation if eye symptoms persist beyond ten days or worsen after initial improvement. A high fever, especially when paired with increasing facial or eye pain, is a significant warning sign.
Immediate medical care is necessary if serious complications are suspected:
- Any changes to vision occur, such as sudden blurriness or the onset of double vision.
- Severe pain when trying to move the eye or an inability to move the eye normally, suggesting the infection may be spreading into the orbital tissues.
- Swelling that rapidly increases, particularly if it causes the eye to bulge forward or is accompanied by confusion.
- If the eye discharge is thick, colored, and accompanied by diffuse redness, a healthcare provider can determine if a secondary bacterial infection is present and requires targeted treatment.