logo-eyezen logo-eyezen logo-varilux-white logo-xperio-uv
Skip to main content

What is "Sleep" In Your Eyes?

By Essilor News

It may sound and look gross, but there's no denying that all of us are familiar with the gunk that appears in our eyes when we wake up in the morning. Whether you call it eye mucus, sleepers, eye discharge, or eye boogers, this build-up is natural.

Eye discharge, or rheum as it's technically known, is a collection of cells, mucus, oil, and debris from the tears that form at the corners of our eyes during sleep. Rheum actually serves a protective function to remove waste products and potentially harmful debris from the front surface of our eyes.

What Causes Eye Discharge?

You might be surprised to learn that our eyes produce mucus throughout the day, but a continuous thin film of tears washes the mucus from our eyes as we blink. Blinking flushes out the rheum before it hardens, but when we're asleep, we aren't blinking. This is why the eye discharge collects at the corners of our eyes overnight, and we wake up with crusty eyes.

Sometimes you'll notice different consistencies to eye discharge. If it's very dry and sandy, that could be a sign of a dry eye problem. On the other side, if it seems gunky and sticky, allergies are most likely to blame.

Contact lens wearers are also more prone to eye discharge because the lenses can irritate the surface of the eye, thus leading the eye to produce more mucus for protection.

How to Safely Wash Away Eye Boogers
When you wake in the morning with that itchy, crusty feeling on your eyes, your natural instinct is to rub the gunk out of your eyes with your hands. But putting your fingers near your eyes is never a good idea, as the germs on your hands could lead to an infection in your eyes.

The best way to clean your eyes of discharge is to lay a washcloth soaked with hot water on the lids and lashes and gently clean them. If your eyes seem to be stickier or glued together, leave the hot washcloth on your eyes for a few minutes.

When to Call the Eye Doctor and How to Tell if You Have Pink Eye?
Eye discharge is generally no cause for alarm, but excessive discharge - especially if it's green or yellow or accompanied by vision issues - should beexamined by an eye doctor. Increased eye mucus may be a sign of a more serious condition, such as pink eye. Below are several pink eye symptoms to watch for:

  • Redness in the white of the eye or inner eyelid
  • Increased amount of tears
  • Thick yellow discharge that crusts over the eyelashes, especially after sleep
  • Green or white discharge from the eye
  • Itchy eyes
  • Burning eyes
  • Blurred vision
  • Increased sensitivity to light
  • Gritty feeling in the eye
  • Swollen eyelids


If you have any of these pink eye symptoms, call your eye doctor to schedule an exam. During the exam, your eye doctor will likely use a cotton swab to collect a sample of fluid from the eyelid to be analyzed. This will confirm the cause of your pink eye and determine the appropriate treatment.

RELATED ARTICLES