Sleeping with your eyes open (nocturnal lagophthalmos): causes, signs and what helps

Sleeping with your eyes open, called nocturnal lagophthalmos, means the eyelids do not fully close in sleep and part of the eye stays uncovered. It is often mild and causes nothing worse than gritty, red eyes on waking, but it can dry the cornea, so it is worth confirming and, when needed, treating.

Lagophthalmos, the medical word for eyelids that do not close fully, is covered in general in my main article on lagophthalmos. This piece is about the night-time version: how common it is, what sits behind it, how to recognise it and what helps.

How common is sleeping with your eyes open?

Common enough that many people have it without knowing. In a Japanese online survey of 2,000 adults, about 4.5% reported a history of physiological nocturnal lagophthalmos, meaning incomplete closure in an otherwise healthy person. The authors set that beside a similar rate reported in Chinese populations and 1.4% reported in Caucasians, so the rate probably differs between populations. It was a questionnaire study, so the figure is self-reported, not measured on examination.

In the same survey, nocturnal lagophthalmos was more common in people with dry eye disease, and it was linked with younger age and with eye symptoms on waking. That is why it is worth asking about when dry eyes are worse in the morning than at night. In Malay it is often searched as tidur mata terbuka, and in Chinese as 睡觉眼睛闭不紧; all three phrases describe the same thing.

Closing the eyes in sleep does a quiet job. The lids spread a film of tears over the cornea and hold it there, and with a gap the film evaporates faster and the surface is left to dry. Even a small gap can matter if it lasts the whole night.

What causes eyelids to stay open during sleep?

Sometimes no cause is found, and sometimes the lid, the nerve or the eye itself is responsible. A published classification divides the causes into those where the eye sits forward (proptosis) and those where the lids fall short of covering it, which the authors call palpebral insufficiency. The common ones are these.

• No disease at all. Physiological nocturnal lagophthalmos is reported to run in families, and alcohol and sleeping tablets (hypnotics) have been reported to make it more likely.
• Facial nerve weakness. Bell's palsy weakens the muscle that closes the lid. I cover it in my article on Bell's palsy and eye protection.
• Thyroid eye disease. The lids retract and the eyes sit forward, which I explain in my article on thyroid eye disease and the cornea.
• Prominent eyes. Eyes that sit forward, whether by build or by disease, leave less lid to cover them.
• Eyelid or brow surgery. Excessive removal of skin or scar tightening can leave a gap, and one case series advises monitoring for nocturnal lagophthalmos after ptosis surgery whatever the result of the Bell's phenomenon check. See my article on eyelid retraction after surgery and dry eye after eyelid surgery.
• Floppy eyelids and sleep apnoea. A loose upper lid that flips over at night is linked with obstructive sleep apnoea, as my article on floppy eyelid syndrome sets out.

What are the signs of sleeping with your eyes open?

The clue is on waking: eyes that feel gritty, red, dry or watery first thing, sometimes blurred until a few blinks have spread the tears. In the Japanese survey, eye symptoms on waking were one of the features linked with nocturnal lagophthalmos. Someone who shares the room may see the whites of the eyes or a glint under the lids, and a partner's photo or video taken in sleep can give a doctor more than a daytime examination can.

It is easy to miss. The classification review notes that obscure lagophthalmos can be hidden by the lashes or by an upper lid that overhangs the lower lid, so a gap that is really there may not be obvious.

How does a doctor check for it?

By watching the lids close, then looking at the surface of the eye. The doctor asks the person to close the eyes gently as in sleep, looks for and measures any gap, and examines the cornea with a slit lamp (a microscope with a light) and fluorescein dye, which stains dry or damaged areas. The classification review says a diagnosis can usually be made with a focused history and slit lamp examination.

The questions matter as much as the instruments: any facial weakness or Bell's palsy, thyroid disease, previous eyelid, brow or facial surgery, medicines and alcohol at night, snoring or witnessed pauses in breathing, and whether the eyes feel worse on waking than at bedtime. The answers point towards the cause, and the cause decides the treatment.

Bell's phenomenon is part of the check. It is the upward and outward roll of the eye when the lids close, a built-in shield that tucks the cornea under the upper lid. If it is strong, the cornea may stay covered even with a gap. A 2024 case series points out that it may vary between individuals and between sleep stages, so what is seen awake does not reliably predict the position of the eye in sleep. A 2025 multicentre study of facial palsy found that lying flat increased the gap by 1.4 mm on average, which is why measuring in the supine position is recommended.

What helps, from mild to severe?

Treatment follows how much of the eye is exposed and whether the cornea is already marked, and the steps overlap.

For exposure in general, the standard approach in the American Academy of Ophthalmology's EyeWiki is frequent preservative-free artificial tears with a lubricating ointment at night. Ointment blurs vision, which is why it belongs at bedtime. A moisture chamber, a clear cover that holds humidity around the eye, gave the greatest protection in a review of hospital intensive care patients. The evidence for home moisture goggles is thinner, but the principle is the same.

Taping the upper lid gently shut is the next step. The NHS lists surgical tape to keep the eye closed at bedtime among the treatments for Bell's palsy. The usual teaching points are to close the lid by hand first, use a gentle paper tape, keep it on the lid skin so it cannot drag the lashes into the eye, and peel it off slowly in the morning. Ask whoever recommends taping to show you once, because tape that lifts in the night can scratch the surface.

Treating the cause comes alongside. That can mean treating thyroid eye disease, asking a prescriber whether a sedating medicine could be the factor (never stop one without advice), having floppy lids assessed for sleep apnoea, or having a lid problem after surgery reviewed. For severe cases, a small gold or platinum weight can be placed in the upper lid so gravity helps it close. In the 2025 study, platinum weights showed less positional variation than gold. Other options in the EyeWiki list include partial suturing of the lids (tarsorrhaphy), lid tightening and, for a temporary effect, botulinum toxin to lower the upper lid for about three months.

When is sleeping with your eyes open urgent?

Pain, sensitivity to light or blurred vision means being seen the same day. An uncovered cornea, the clear front of the eye, can be damaged, and EyeWiki lists ulceration, microbial keratitis (infection) and permanent vision loss from scarring as the risks of exposure keratopathy. A red eye with discharge, or a white or grey spot on the cornea, belongs in the same category.

A sudden droop of one side of the face needs urgent medical assessment; the NHS advises urgent help for symptoms of Bell's palsy because treatment works better when started within 72 hours. If you cannot reach an eye doctor, go to an eye casualty or emergency department. For everything else, more on the area is in the eyelid conditions section and my hub article on why eyes look tired.