A person's eyes produce mucus or pus known as rheum that leaves behind what are colloquially called eye boogers.
When mucus dries in the eyes, it can leave behind this sludgy substance. Some people refer to it as having "sleep" in the eyes.
Mucus helps protect the eyes from specks of dirt, harmful chemicals, and other foreign materials. Eye boogers are harmless, but changes in discharge from the eyes can give clues to health concerns someone may have.
Eye boogers refer to a buildup of mucus in the eyes.
During the day, each time a person blinks, the eyes flush away the secretions of rheum they have produced. Since the eyes produce this mucus in such small quantities, most people never notice it.
At night, when a person does not blink, the mucus can build up. Sealed eyelids allow it to build up along the eyelashes and in the tear ducts.
Everyone produces the mucus that causes eye boogers. This is normal in healthy eyes. However, some changes in lifestyle or eye health may cause the eyes to produce excess mucus. These changes can also make it more likely that the rheum sticks to the eyes.
Causes of excess mucus include:
- Eye products: Some eye products, such as cosmetics or contact lenses, may irritate the eyes and cause them to produce more mucus.
- Dirt and debris near the eyes: When the eyes have accumulated debris around them, such as when a person sleeps without cleaning off mascara, they can become irritated. The eyes will produce extra mucus that can then get trapped in the eyes and on the eyelashes.
- Changes in the weather or climate: Some people produce more discharge at certain times of the year, such as during allergy season or cold weather.
Healthy rheum is clear or light yellow. It may be hard, sludgy, or thin after sleeping, but should not be noticeable during the day.
If the mucus is very thick, green, dark yellow or occurs with pain or redness in the eyes, it could be a sign of an eye infection. Anyone with these symptoms should see an eye doctor quickly.
In addition to healthy mucus, there are many other types of eye discharge. Some infections and eye health conditions may cause abnormal or painful eye discharge.
Types of eye discharge include:
- Conjunctivitis or pink eye: Pink eye causes the eye to be red and irritated. There may be green, white, or yellow discharge. Some people feel like something is trapped in the eye. This can be caused by bacteria, virus, or an allergic reaction.
- Bacterial conjunctivitis or other eye infections: Some forms of conjunctivitis are bacterial and require antibiotics. These infections can make the eye pink and swollen, painful, and may cause a fever.
- Stye or chalazion: Styes and chalazia are blocked glands in the eyelids. They usually cause a swelling or lump. They can be painful and itchy but usually go away on their own with warm compresses.
- Eye injury: An injury to the eye, such as a scratched cornea, can cause the eye to swell and itch. It may feel as if there is something in the eye. If the injury becomes infected, there may be thick discharge.
- A blocked tear duct: This can cause sticky, thick eye mucus, and may be painful.
- An object in the eye: Contact lenses can dry up and become stuck in the eye and may roll near the top of the eyelid. An eyelash or other small object can also irritate the eye. The eye will become very watery and tender and may be sensitive to light and produce mucus.
Babies produce eye mucus and may develop eye infections. A baby who has eye discharge similar to that of an adult is usually healthy, however.
Some newborns have tear ducts that are not fully developed. This can cause the ducts to become blocked. Babies with blocked tear ducts may have green or yellow mucus all day and not just when they wake up. This can usually be managed at home with warm compresses.
If the eye becomes tender, red, or swollen, the baby may have an infection and will need to see a doctor.
Children whose blocked tear ducts do not improve by their first birthday may need surgery to open the tear duct.
Most eye boogers are a sign that the eye is healthy and that it is getting rid of dirt and debris.
Good eye hygiene, including removing makeup at night and keeping the eyes clean by wiping the closed eyes with a clean, warm washcloth, can help reduce the eye discharge.
In people with dry eyes, eye drops may also help. Eye drops from different brands are available online, though speaking with a doctor before purchasing is recommended to ensure the product is safe to use.
People with contacts lenses who want to reduce their eye boogers should remove their contacts at night. They should also replace their contacts as directed by their eye doctor and use the appropriate solutions to clean their lenses.
Some people notice more eye boogers after sleeping. A warm compress held over the eyes for 3–5 minutes can help loosen the mucus.
If there is enough discharge to cause the eyelids to stick shut in the morning, a person should speak to an eye doctor to rule out an infection.
Eye boogers are normal and not a sign that something is wrong. Some eye infections also cause similar symptoms, however, so it is important to know the difference between normal and harmful eye discharge.
Prompt treatment of an eye infection can prevent it getting worse. It may even save a person's vision.
Some signs that eye discharge could be a problem include:
- a sudden change in discharge
- painful discharge
- red eyes
- discharge after an eye injury
- pain in the eyes
- light sensitivity
- changes in vision
The eyes must constantly protect themselves from invading materials, including dust, dander, mascara, and pet hairs. By producing a healthy discharge, the eyes clean themselves and reduce the risk of infection.
A person can help keep their eyes healthy by monitoring eye discharge. Knowing what is normal can help people decide when to see an eye doctor.