Eye mucus, medically known as rheum or eye discharge, serves a protective function for the eyes. It is a combination of mucus, oil, skin cells, and other debris that helps keep the eye surface clean and lubricated. While the eyes continuously produce this discharge, blinking typically washes it away throughout the day. However, during sleep, when blinking ceases, this discharge can accumulate in the corners of the eyes.
Normal vs. Abnormal Eye Mucus
Normal eye discharge is minimal and appears as a crusty, clear, or whitish substance, often found upon waking. This “sleep” in the eyes is easily wiped away and is a natural part of the eye’s self-cleaning process. In contrast, white stringy mucus is not normal and indicates an underlying issue. This abnormal discharge often appears ropy, sticky, or as thin threads, and can be persistent or excessive.
Common Causes of White Stringy Mucus
Several conditions can lead to white stringy mucus in the eyes, each with accompanying symptoms. Understanding these causes helps identify the source.
Dry eye syndrome
Dry eye syndrome occurs when the eyes do not produce enough tears, or the tears produced are of poor quality. When the watery component of tears is insufficient, the remaining mucus and oil components can become concentrated, leading to thick, stringy mucus. Individuals with dry eyes experience stinging, burning, or grittiness, along with redness and sometimes watery eyes.
Allergic conjunctivitis
Allergic conjunctivitis results from the eye’s immune response to allergens like pollen, dust, or pet dander. This allergic reaction triggers inflammation, causing the eyes to produce excessive, sticky, and often stringy mucus. Common symptoms include intense itching, redness, swollen eyelids, and watery discharge, often accompanied by sneezing or a runny nose.
Bacterial conjunctivitis
Bacterial conjunctivitis, an infection of the conjunctiva, can lead to purulent, often stringy discharge. This discharge may appear white, yellow, or green due to the presence of white blood cells fighting the infection. Other symptoms include significant redness, crusting of the eyelids making them stick together, and general eye irritation.
Viral conjunctivitis
Viral conjunctivitis, caused by common cold viruses, can also produce eye discharge that may become stringy. This type of discharge is more watery than bacterial discharge but can still contain mucus. Symptoms include eye redness, a gritty sensation, irritation, and sometimes a sore throat or runny nose.
Blepharitis
Blepharitis is an inflammation of the eyelids, particularly along the lash line. This condition disrupts the normal function of oil glands in the eyelids, leading to an abnormal tear film composition and the production of frothy or stringy mucus. Associated symptoms include eyelid redness, swelling, itching, a gritty or burning sensation, and crusting of the eyelashes.
Blocked tear duct
A blocked tear duct prevents tears from draining properly, causing them to back up. This stagnation can lead to mucus accumulation, which may manifest as stringy discharge, especially in the inner corner of the eye. Excessive tearing, swelling, and redness near the inner corner of the eye are common signs.
Foreign objects or persistent irritation
Foreign objects or persistent irritation can also stimulate increased mucus production in the eye. The eye attempts to flush out the irritant by producing more tears and mucus, which may appear stringy. This can result from exposure to environmental factors such as smoke, wind, or dust.
When to Consult a Healthcare Professional
While occasional white stringy mucus might be benign, certain signs indicate professional medical evaluation is needed. Consult an eye care specialist if the stringy mucus is persistent or worsens. Seek medical attention for increased pain, significant vision changes like blurriness or light sensitivity, or severe eye redness. Pus-like discharge, especially if green or yellow, or matted eyelids also warrant prompt medical advice.
If eye symptoms are accompanied by systemic issues like fever, seek professional care. Self-diagnosis is not recommended; a healthcare provider can determine the cause and recommend treatment.