Eye discharge, often referred to as “sleep” in the eyes, is a natural byproduct of the eye’s self-cleaning process. This material is a mixture of mucus, oil, exfoliated skin cells, and debris that accumulates while you are asleep. While a small amount of crust upon waking is expected, a noticeable increase in volume, a change in color, or a difference in consistency often signals that the body is reacting to an irritant, infection, or underlying condition.
Normal Discharge vs. Concerning Changes
The discharge that collects in the corners of the eyes overnight is usually clear or a faint, whitish-gray color. This material is typically thin, drying into a small, crusty formation that can be easily wiped away. During the day, the constant action of blinking spreads the tear film, which washes this debris away before it has a chance to solidify.
A change from this baseline signals that the eye is working harder to clear a problem. Concerning changes include a significant increase in volume that appears throughout the day, not just upon waking. The discharge may become so sticky that it glues the eyelids completely shut, making it difficult to open the eyes in the morning.
The color of the discharge is a reliable indicator of the underlying cause. Clear or light-colored discharge is often associated with non-infectious causes. A shift to a distinct yellow or green hue is a significant sign, indicating the presence of white blood cells and a common response to a bacterial infection. Increased discharge accompanied by symptoms like redness, pain, or blurred vision should also be viewed as concerning.
Common Infections That Increase Discharge
Infections are a frequent reason for a sudden and dramatic increase in eye discharge, varying significantly depending on the pathogen. The two most common infectious causes are viral and bacterial conjunctivitis, both of which inflame the transparent membrane covering the eye and inner eyelid.
Viral conjunctivitis, often caused by the same viruses that cause the common cold, typically produces thin and watery discharge, sometimes described as excessive tearing. This discharge may include a small amount of white or light yellow mucus, making the eyes slightly sticky upon waking. Viral conjunctivitis is highly contagious and frequently starts in one eye before quickly spreading to the other.
Bacterial conjunctivitis results in a much thicker, heavier, and pus-like discharge. This discharge is often distinctly yellow, green, or gray due to the high concentration of inflammatory cells fighting the bacteria. The sticky, purulent material commonly causes the eyelids to be completely matted shut in the morning, often requiring a warm compress to loosen them.
Infections can also be localized to the eyelid structure, such as in the case of a stye or blepharitis. A stye is an acute infection of an oil gland near the base of an eyelash, which may produce a small amount of pus as the infection drains. Blepharitis, an inflammation of the eyelid margins, is often chronic and causes a foamy or greasy discharge along with crusting at the base of the lashes due to clogged oil glands.
Non-Infectious Causes of Increased Eye Discharge
Not all instances of excessive eye discharge are caused by a contagious infection; many result from the eye reacting to environmental factors or chronic conditions. Allergies are a common culprit, causing a condition known as allergic conjunctivitis. This reaction to substances like pollen or dust mites typically results in profuse, thin, and watery discharge, often accompanied by intense itching in both eyes.
The discharge from allergic reactions can sometimes contain thin, stringy strands of mucus. This stringy mucus is also characteristic of Dry Eye Syndrome. When the eyes are too dry, the body compensates by producing an unstable, excessive watery reflex tear that contains a high concentration of mucus.
Contact lens misuse or poor hygiene can trigger increased discharge due to constant irritation or localized inflammation. Wearing lenses longer than recommended or failing to clean them properly can irritate the cornea and conjunctiva. This irritation sometimes manifests as giant papillary conjunctivitis, where bumps form on the inner surface of the eyelid, causing mucus production.
The presence of a foreign body, such as dust, grit, or a loose eyelash, causes the eye to overproduce tears and mucus in an effort to flush out the irritant. This response is usually immediate and resolves quickly once the foreign particle is removed. Increased discharge can also be a side effect of certain medications or chronic conditions affecting tear production.
When to Consult a Doctor
Minor increases in eye discharge can often be managed with simple home care, but certain signs require professional medical evaluation. Any discharge that is thick, distinctly yellow, or green requires a consultation, as these colors suggest a bacterial infection that may need prescription treatment. A doctor should be seen if the discharge is so heavy that it consistently glues the eyes shut, or if it persists for more than two days without improvement.
Additional symptoms accompanying the discharge serve as red flags indicating a potentially more serious issue. These include the onset of eye pain, a sudden change in vision quality, or increased sensitivity to light (photophobia). Swelling around the eye or an intense, deep redness in the white part of the eye also warrant prompt medical attention.
If the eye discharge is accompanied by systemic symptoms, such as a fever, a severe headache, or swelling of the lymph nodes in front of the ear, seek care immediately. These signs can point to a more widespread or complex infection. Gently cleaning the eyelids with a warm, clean cloth can help remove crusting at home.