Sleep crust is a combination of skin cells, tears, and mucus that accumulates naturally during sleep. Sometimes, sleep crust may signal an eye infection or other conditions.
Sleep crust, which people may also call eye gunk or simply “sleep,” is fairly common. It comprises a combination of mucus, tears, and skin cells. The medical term for sleep crust is rheum.
In this article, we explore the causes of eye crust, how to treat crusty eyes, when to seek medical help, and eyelid hygiene tips.
Certain conditions or situations can cause or increase the amount of crust someone experiences in the morning. These can include:
Blinking tends to wipe away dead skin cells, dust, mucus, and tears from the eyes. As people sleep, blinking stops, but the eyes continue to wash out these waste products. This is to ensure that the eyes stay clean.
Some people may notice a crusty film in the corner of the eyelids upon waking. This is a buildup of moisture in the eye that typically washes away impurities.
When someone has a chronic dry eye condition, the eye may produce a lot of mucus to compensate for the dryness. The mucus can appear ropey or stringy and accumulates throughout the day or night. In the morning, people may notice a lot of sticky or gritty crust.
Allergies can irritate the eye and trigger more mucus production.
With seasonal allergies, people may notice more eye crustiness than usual in the mornings. A few contributing factors, such as rubbing the eyes, inflammation, and increased production of tears, can also play a role.
Blepharitis affects the area where eyelashes grow, causing it to become red, irritated, or itchy. People with this condition may experience more eye crustiness in the morning.
There are numerous possible causes of blepharitis. One common symptom of blepharitis is a crusty discharge.
Other symptoms of blepharitis include:
- frothy or foamy tears
- eyelids sticking together
- a stinging or burning sensation in the eyes
- flakes of skin at the base of the eyelid
- eyes producing too much or too little tears
- light sensitivity
When someone has an infection in one or both eyes, they may notice more eye crust in the morning than usual.
Pink eye (or infective conjunctivitis) is when inflammation occurs in the conjunctiva — the thin membrane lining the eye. Both bacteria and viruses
Other symptoms of infective conjunctivitis include:
- a watery discharge or buildup in the eye
- redness and irritation of the eye
- a gritty feeling underneath the eyelids, which the buildup of watery discharge causes
If someone has a stye, they may notice that just one of their eyes becomes crustier in the morning than usual. The main symptom of a
Styes can be painful and may produce a yellowish mucus buildup in the corners of the eye.
Blocked tear duct
When a person’s tear ducts become blocked, it prevents normal eye drainage. They can experience more eye crust in the morning.
Generally, a person with a blocked tear duct may notice small lumps of white or yellowish mucus accumulate in the corners of the eyes.
Other signs someone may have a blocked tear duct include:
- pain and discomfort
If a person is experiencing crusty eyes in the morning but has no other symptoms that suggest an infection or other condition, they can usually treat them at home.
The American Academy of Ophthalmology advises people to wash their hands before trying to rub anything out of their eyes. This measure helps prevent infection, as bacteria and germs often cover the hands.
A person can try gently applying a clean, moist washcloth to the eye area to wash it with warm water. This should cause the crust to break up and dissolve.
Proper eye hygiene habits can help prevent a buildup of eye crust when a person wakes up in the morning. They may wish to try the following:
- washing the face before bed and gently cleansing the eye area with a clean, damp washcloth
- taking out contact lenses before going to sleep
- completely removing any eye makeup using wipes or a makeup remover and cotton pads before sleeping
- not touching or rubbing the eyes with unwashed hands during the day and night
If a person is experiencing additional eye symptoms alongside crusty eyes in the morning, they may require prescription medications or other treatments.
A person should contact a doctor if they have the following:
- increased sensitivity to light
- blurred vision
- redness and irritation
- difficulty opening your eye
- dark yellow or green discharge
Eye doctors — such as ophthalmologists or optometrists — can examine someone to determine what is causing their symptoms and treat the condition. They may prescribe eye drops to treat chronic dry eye or antibiotics to treat inflammation or infection.
For many people, waking up with crusty eyes in the morning is very common. The buildup of fluid that washes away dirt, dust, and other environmental irritants can dry, harden, and form a crust.
A person can often wash away the crust from the eyes with a clean washcloth soaked in warm water. If someone experiences additional symptoms such as pain, redness, or difficulty opening and closing one or both eyes, they may wish to speak with a doctor who can diagnose other conditions.
People can minimize or prevent the buildup of eye crust by practicing proper eye hygiene habits.