The whitish substance sometimes collected in the inner corners of your eyes, often called “sleep in your eyes” or “eye boogers,” is a normal part of the eye’s self-cleaning process. While its appearance might seem unusual, it generally indicates healthy ocular function.
The Science of Eye Discharge
The human eye constantly produces a tear film that coats its surface, providing lubrication and protection. This tear film and eye discharge, known scientifically as rheum, are complex mixtures of biological components.
Rheum primarily consists of mucus, secreted by goblet cells in the conjunctiva (the clear membrane covering the white of the eye and lining the eyelids). Mucus helps lubricate the eye and trap debris. It also contains oils from meibomian glands along the eyelids. These oils form the tear film’s outermost layer, preventing evaporation and maintaining eye lubrication. Dead skin cells, dust, and other tiny particles are also entrapped within this mixture.
During waking hours, blinking distributes the tear film, flushing away rheum through the tear drainage system. When you sleep, blinking ceases, allowing these components to collect. Gravity and eyelid movement then push this mixture towards the tear ducts, where it dries and forms visible discharge.
What Normal Eye Discharge Looks Like
Healthy eye discharge typically appears as a small, whitish or slightly yellowish substance. Its consistency can vary, ranging from moist and sticky to dry and crusty, depending on liquid evaporation overnight. This normal accumulation is part of the eye’s natural defense, removing waste products and debris from the ocular surface.
Normal eye discharge is easy to remove and causes no discomfort, redness, or vision changes. It signifies the eye’s cleaning system functions as intended, maintaining a clear, healthy surface. This “sleep crust” upon waking is a routine physiological event and not a cause for concern.
When Eye Discharge Is a Concern
While some eye discharge is normal, certain characteristics can indicate an underlying medical condition. A change in discharge color, such as green, yellow, or grey, often suggests a bacterial infection. Bacterial conjunctivitis (pink eye), for example, often presents with thick, sticky, pus-like yellow or green discharge that can glue eyelids shut.
Changes in consistency (excessively thick, watery, or stringy) or increased quantity persisting throughout the day also signal a potential problem. Accompanying symptoms like eye pain, redness, itching, swelling, light sensitivity, blurred vision, or a persistent foreign object sensation indicate abnormal discharge. Dry eye can lead to stringy, white mucus, while a blocked tear duct might cause persistent watery or sticky discharge.
Safe Practices for Eye Care
Maintaining good eye hygiene can help manage normal eye discharge and reduce the risk of irritation or infection. When removing eye discharge, use a clean, damp cloth or cotton ball. Gently wipe from the inner corner of the eye outwards, using a fresh part of the cloth for each wipe to avoid spreading contaminants. Applying a warm compress to closed eyes can soften crusty discharge for easier removal.
Avoid rubbing your eyes with unwashed hands, as this introduces bacteria and worsens irritation. Wash hands frequently, especially before and after touching eyes. To prevent spread, do not share eye makeup, towels, or other personal items.
If eye discharge changes in color, consistency, or quantity, becomes persistent, or is accompanied by pain, redness, blurred vision, or light sensitivity, consult an eye care specialist.