Many cultures have stories about a Sandman who puts people to sleep by sprinkling sand in their eyes. In the morning, they wake up and rub the crusty sand from their eyes. In reality, this “sand” is eye discharge that collects in the corners of our eyes while we sleep. There are many causes of eye discharge, though it is generally harmless. Types and colors of eye mucus can also indicate various causes or conditions.
Though we may only notice it after waking up, healthy individuals are always creating eye discharge consisting of mucus, skin cells, oil, and other debris. While we’re awake, constant blinking washes away eye discharge through the tear ducts. But humans don’t blink while asleep, so eye discharge accumulates at the edges of the eyes. Eye infections, eyelid inflammation, and styes can change the appearance of eye discharge.
Sometimes excess oils, bacteria, or other substances clog the eyelid glands. These clogged glands develop into small, red bumps on the interior or exterior of the eyelids. These harmless styes can become infected, at which point the stye begins to resemble a pimple and secrete yellow mucus. In some cases, the affected eye may feel bruised and be sensitive to light. Though it can be tempting to pop the stye, doing so could result in a dangerous skin infection.
If the eyelids are inflamed, eye discharge can become thick and crusty. Medical professionals call eyelid inflammation blepharitis. Blepharitis is usually not a serious issue, though it can be uncomfortable and cause the eyes and eyelids to develop a red coloration. The crusty eye discharge can collect on the eyelashes and cause them to stick together. Some cases of blepharitis cause the skin around the eyes to flake. Often, blepharitis will lead to other conditions, such as pink eye.
Most eye discharge is not the result of a serious illness. However, green or gray mucus with a thick consistency suggests an eye infection. Conjunctivitis is the medical term for pink eye. Bacterial conjunctivitis is a highly contagious infection that causes swelling and irritation. The source bacteria, pyogenic, by definition means producing pus.
Pollen, perfumes, smoke, and air pollution can all trigger allergic responses in people with allergies. Professionals estimate between six and 30 percent of the population experience eye allergies. Problematic substances cause the eyes to become watery, red, sore, and itchy. Sometimes, allergies cause inflammation or allergic conjunctivitis. As part of the allergic response, the eyes may produce stringy, white mucus. This eye discharge collects inside or under the lower eyelid.
Some conditions, such as viral conjunctivitis, can cause tears to mix with eye mucus, resulting in watery, slightly transparent eye discharge. Viral conjunctivitis is contagious and antiviral therapies are not effective in treating it. These factors lead to widespread outbreaks in shared spaces such as schools, nursing homes, and offices. While awake, viral conjunctivitis may cause the eyes to water excessively. Normally, excess tears flow from the tear duct into the nasal cavity. However, if there is too much fluid, the nose can run as well.
One of the most common types of eye discharge is small, dry particles of mucus. These particles are often the result of dry eyes or dry eye syndrome. When a person’s eyes are too dry, their eye discharge doesn’t have enough water to flow down the tear duct. Instead, the mucus, oil, and other substances stick together and collect in the corners of the eyes. There are many reasons a person may have dry eyes, including medications, age, and hormonal changes.
Many newborns do not have fully developed tear ducts. Despite this, infants still create eye discharge. Because the tear ducts are not large enough, the eye discharge may block the ducts. As a result, infants sometimes accumulate green or yellow mucus around their eyes even while awake. Generally, eye mucus is not a sign of an eye infection at this age. Instead, signs of infant eye infections include the eye becoming red, swollen, or tender. Children whose tear ducts do not develop fully by their first birthday may require surgery.
Eye discharge treatment depends on the underlying cause.
Gently cleaning the eyes with a warm, clean washcloth can help manage eye infections and conditions.
There is no safe method to prevent eye discharge while sleeping. However, it is fairly simple to avoid contracting illnesses that worsen discharge. For example, avoiding large groups is an effective way to avoid infectious conjunctivitis. Refrain from touching your eyes to prevent spreading bacteria. Changing and washing pillowcases often can also help prevent eye infections. Sharing towels and washcloths increases the risk of infection.
This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.