“Sleep in eyes,” often called eye gunk or rheum, is a common occurrence upon waking. This substance is a natural accumulation of mucus, oils, shed skin cells, and environmental debris. It is a normal part of how the eyes maintain cleanliness and health. For most individuals, a small amount of “sleep” in the morning is routine and harmless.
The Science Behind Eye Discharge
The eyes are protected by the tear film, a thin layer covering the eye’s surface. This film consists of three main layers: an oily outer layer produced by meibomian glands, a watery middle layer, and an inner mucin layer produced by goblet cells. The tear film’s primary functions include lubricating the eye, providing nutrients to the cornea, and ensuring a smooth surface for clear vision. It also acts as a cleansing mechanism, helping to flush away foreign particles and debris.
Throughout the day, blinking spreads the tear film across the eye, washing away accumulated dust, old cells, or excess mucus into the tear drainage system. This continuous blinking action prevents substances from building up. However, during sleep, the eyes are closed, and blinking ceases.
Without the flushing effect of blinking, natural secretions and debris begin to collect. This mixture of mucus, oils, tears, and dead skin cells gathers in the corners of the eyes and along the lash line. As the liquid component evaporates overnight, it forms the crusty or sticky substance known as “sleep in eyes.”
Normal Versus Concerning Eye Discharge
Normal eye discharge is typically small, appearing as a clear, white, or pale cream-colored substance. It may be slightly crusty or sticky and is usually easy to wipe away from the eye corners. This type of discharge is a healthy indication that the eyes are effectively cleaning themselves of natural byproducts and environmental particles.
Changes in the characteristics of eye discharge can signal an underlying issue. For instance, excessive amounts of discharge, or discharge that changes color to yellow or green, might suggest an infection. A thick, sticky, or foamy consistency, along with symptoms like eye redness, itching, pain, light sensitivity, or blurred vision, can also be signs of a problem.
Conditions like conjunctivitis (pink eye) can cause varying types of discharge depending on if it is viral, bacterial, or allergic. Blepharitis, an eyelid inflammation, often leads to crusty or sticky discharge along the lash line. Blocked tear ducts can also result in watery eyes and sticky white or yellow discharge.
Maintaining Eye Health
Managing normal eye discharge involves simple hygiene practices to keep eyes clean and comfortable. Gently wiping away accumulated “sleep” with a warm, damp, clean cloth is effective. Avoid rubbing eyes, as this can introduce germs or irritate the delicate eye area.
Regular hand washing before and after touching eyes helps prevent the transfer of bacteria. While some eye discharge is expected, consult an eye care professional if you notice a significant increase, a change in color or consistency, or if it is accompanied by other symptoms like pain, vision changes, redness, or swelling.