Rheum, often recognized by common names like “sleep crust,” “eye gunk,” or “eye boogers,” refers to the thin mucus that naturally collects in and around the eyes. This substance is a normal byproduct of your body’s self-cleaning processes. It appears most noticeably after sleep, serving a protective function for eye health.
What is Normal Eye Rheum?
Normal eye rheum forms from a combination of mucus produced by the conjunctiva, an oily substance called meibum from the meibomian glands, tears, old skin cells, and environmental debris such as dust. This mixture continuously cleanses the eye’s surface throughout the day. Each blink spreads the tear film across the eye, washing away this discharge into the nasolacrimal duct.
During sleep, blinking ceases, allowing these components to accumulate at the corners of the eyes and along the lash lines. The watery part of the tears can evaporate, leaving behind a crusty or sticky residue. Normal rheum typically appears clear, whitish, or a pale cream color, and is usually easily wiped away upon waking.
Signs of Problematic Eye Rheum
Changes in eye rheum characteristics can indicate an underlying health issue. A change in color is a key sign; green, yellow, or gray rheum may suggest an infection. Thick, sticky yellow or green discharge often indicates bacterial infections, while viral infections might produce clear or slightly cloudy discharge.
Consistency also provides clues. Problematic rheum might be unusually thick, sticky, stringy, or excessively watery. Stringy white mucus can be a symptom of allergic conjunctivitis. Thick, crusty mucus along the eyelashes, especially if accompanied by redness, can suggest eyelid inflammation like blepharitis.
An increase in the amount of discharge or its persistence throughout the day indicates a potential problem. If rheum is so abundant that it temporarily seals your eyelids shut in the morning, it could be a sign of infection. Problematic discharge is often accompanied by other symptoms, including eye pain, itching, redness, eyelid swelling, or a gritty sensation. Blurred vision, light sensitivity, or a feeling of a foreign body in the eye are also associated symptoms.
When to Seek Medical Advice
Seek medical evaluation if eye rheum shows concerning changes or is accompanied by other symptoms. Contact an eye doctor or general practitioner if the discharge is persistent or worsening, or if its color, consistency, or amount is unusual for you. Immediate medical attention is warranted if the rheum is accompanied by eye pain, significant redness, or changes in vision, such as blurriness or light sensitivity.
If rheum prevents your eyes from opening in the morning, or if you experience fever along with eye symptoms, consult a healthcare provider. For infants and young children, any yellow or green eye discharge, swollen eyelids, or persistent watery eyes should prompt a medical visit.