Lagophthalmos is a condition that prevents your eyes from closing completely. If the problem only happens when you sleep, it’s called nocturnal lagophthalmos.

The condition itself is usually harmless, but it does leave your eyes vulnerable to damage.

Lagophthalmos can also be a symptom of more serious conditions, so it’s important to contact your doctor if you have trouble blinking or closing your eyes to sleep.

The main symptom of lagophthalmos is being unable to close your eyes. If you have nocturnal lagophthalmos, you might not even know it. Look for these additional symptoms in one or both eyes if you think you have lagophthalmos:

  • increased tears
  • foreign body sensation, which is the feeling that something is rubbing against your eye
  • pain or irritation, especially in the morning

A variety of things can cause lagophthalmos, but they mostly fall within two categories.

The first is damage to the seventh cranial nerve, which controls the muscles in your eyelid. This is also known as the facial nerve. Many things can cause damage to the facial nerve, including:

The second group of causes involves damaged eyelids, which can result from the following:

  • scarring from burns, injuries, or certain medical conditions, such as Stevens-Johnson syndrome
  • eyelid surgery
  • floppy eyelid syndrome

Protruding and sunken eyes can also lead to lagophthalmos.

Using your medical history and a physical exam, your doctor will try to figure out the underlying cause of lagophthalmos. Make sure you tell your doctor about any recent injuries or infections they don’t know about.

Your doctor will also probably perform some tests. You may be asked to look down while trying to close your eyes. Your doctor will measure the space between your eyelids with a ruler. They might also record how often you blink, and how much your eyes close when you do. The amount of force you use to close your eyes can also help your doctor figure out if the facial nerve is involved.

They’ll probably also do a slit lamp exam, which involves using a microscope and bright light to look get a better look at your eyes. Your doctor may also do a fluorescein eye stain test to see if there are any signs of damage to your eye.

There are several surgical and nonsurgical treatment options for lagophthalmos.

Surgical treatment

Changing the position of either the top or bottom eyelid can treat or improve the symptoms of lagophthalmos. Another procedure involves implanting gold weights into the upper eyelid, which allows the eyes to close using gravity.

If lagophthalmos is caused by a temporary condition, your doctor may suggest tarsorrhaphy. This involves temporarily sewing your eyelids together, either completely or partially. Keeping the eye covered helps to prevent any additional damage to it while you recover from the underlying condition.

If the underlying condition is going to take some time to heal, your doctor may do a permanent tarsorrhaphy. They’ll likely leave a small opening so you can still see. Once you’ve healed, your doctor will enlarge the opening.

For severe lagophthalmos related to a paralyzed facial nerve, your doctor may suggest a procedure that provides more support for the eyelid. These include nerve and muscle transfers, implants, and facial reanimation procedures.

Nonsurgical treatment

Nonsurgical treatment options tend to focus on treating the symptoms of lagophthalmos, rather than the condition itself. Applying artificial tears (Visine Pure Tears, Refresh) throughout the day can help to prevent your eyes from drying out and itching. You can also apply a protective ointment to your cornea throughout the day to prevent scratches.

If you have nocturnal lagophthalmos, moisture googles may help protect and moisturize your eyes while you sleep. You can also keep a humidifier nearby while you sleep for added moisture. Your doctor may suggest putting small weights on the outsides of your eyelids to keep them closed. Surgical tape can provide the same effect.

Untreated lagophthalmos leaves your eyes vulnerable to scratches and other injuries because they aren’t protected by your eyelids.

Ongoing exposure of your eyes can also lead to exposure keratopathy, which has the same symptoms as lagophthalmos. Exposure keratopathy can eventually cause your cornea, the clear front part of your eye, to either swell or thin. It can also cause a corneal ulcer.

Surgery to treat lagophthalmos may also have complications. Tarsorrhaphy can leave permanent scarring, while gold weight implants can start to move away from their original placement. Make sure you follow your doctor’s post-surgery instructions to avoid additional problems.

Lagophthalmos isn’t a dangerous condition, but it can eventually lead to eye problems. Work with your doctor to figure out the underlying cause. Depending on the cause, you can treat lagophthalmos with either surgery or products to help keep your eyes moisturized and protected.