Sleeping with your eyes open: nocturnal lagophthalmos

If your eyes are at their worst in the first minute after waking, gritty, burning, red, with vision that clears only after several blinks, one explanation worth ruling out is that your eyelids are not fully closing while you sleep. The clinical name is nocturnal lagophthalmos, and Latkany and colleagues define it plainly as the inability to close the eyelids during sleep.

The gap is often small enough that nobody has ever noticed it. Even a narrow strip of lower cornea left uncovered dries out over six or eight hours of sleep, night after night, and the overview does not put a figure on how wide that gap typically is. Latkany's overview describes lagophthalmos as associated with exposure keratopathy, poor sleep and persistent exposure-related symptoms, which is a fair summary of why it is worth finding.

How common it is, we cannot tell you precisely. That overview does not give a prevalence figure, and we are not going to invent one. What can be said is that it is easy to miss, because most people have no idea what their own eyelids do once they are asleep.

What is actually happening overnight

Tear production falls during sleep, and the closed eye is meant to be a sealed, humid space that does not need much. That arrangement only works if the lids meet. When a strip of cornea and conjunctiva stays exposed instead, it dries for the whole night with no blinking to rescue it.

The DEWS II pathophysiology report sets out the general mechanism: evaporative water loss leads to hyperosmolar tissue damage which, either directly or by inducing inflammation, causes a loss of epithelial and goblet cells. The consequent decrease in surface wettability leads to early tear film break-up and amplifies the hyperosmolarity in a vicious circle. Among the damage patterns the report lists is punctate epithelial keratitis, the fine scattered surface damage a clinician sees with a dye.

In lagophthalmos, that damage sits where the exposure sits. This is why the pattern matters more than its presence: staining spread across the lower third of the cornea, in a band, points somewhere quite different from staining scattered evenly over the whole surface.

What causes it

Latkany and colleagues group the causes into two families: proptosis and eye-exposure causes, and palpebral, meaning eyelid, insufficiency causes. In everyday terms, either the eye sits too far forward for the lids to cover it, or the lids themselves are not doing their job.

On the exposure side, the common contributor is thyroid eye disease, which pushes the eye forward and pulls the upper lid up, so the lids have further to travel and a wider aperture to close. Prominent eyes in shallow orbits do the same thing without any disease being involved at all.

On the eyelid side, the causes are mechanical. Facial nerve weakness, whether from Bell's palsy, a stroke or surgery near the nerve, weakens the muscle that closes the lid. Previous eyelid or brow surgery, particularly upper lid blepharoplasty, can leave the lids fractionally short. Scarring from trauma, burns or long-standing skin disease tethers the lid. Lid laxity with age, and floppy eyelids that turn out easily when pulled, both reduce the quality of the seal.

Two more factors come up regularly in clinic and deserve to be flagged with appropriate caution. Sedating medicines, deep sedation and alcohol are widely described as reducing how completely the lids close, and sleeping face-down with the pillow dragging on a lid can do it mechanically. Neither point is quantified in the overview cited here, so treat them as clinical observation rather than measured fact.

How it gets spotted

The single most useful piece of history is somebody else's. If a partner has ever said your eyes look half open when you are asleep, that is worth more than any symptom you can describe yourself. A photograph taken by someone else after you have dropped off is the next best thing.

The symptom pattern is the other clue. Nocturnal lagophthalmos is a morning problem that eases through the day, the reverse of the classic evaporative pattern that builds through the afternoon. If your mornings are the worst part of the day, our piece on why eyes are dry in the morning covers the other explanations that belong in the same conversation.

At the examination, Latkany and colleagues note that a diagnosis can usually be made with a focused history and slit lamp examination. The clinician watches a gentle closure, looks for a residual gap, and then puts in a drop of fluorescein to see where the surface is damaged. Inferior corneal staining in an otherwise unremarkable eye is the finding that raises the question.

The same paper makes an important point about what gets missed. Obvious lagophthalmos is usually detected, but obscure lagophthalmos is sometimes difficult to recognise, either because the eyelashes obstruct the view or because the upper lid overhangs in front of and below the highest part of the lower lid when the eye is closed. The lids look shut. They are not sealed. That is precisely why a normal-looking closure in the chair does not settle the matter, and why the staining pattern and the history carry so much weight. Our guide to the tests used in a dry eye assessment explains what else is usually done at the same visit.

What can be done about it

Latkany and colleagues describe treatment as multipronged, and list minor procedures or ocular surgery to correct lid malposition, natural, topical or oral agents, and punctal plugs to manage the ocular surface effects. In practice an optometrist works up from the least invasive end of that list.

An ointment at night is usually where it starts. Ointments are far thicker than drops and stay put for hours, which is exactly what an exposed strip of cornea needs. They will blur your vision, so they go in once you are in bed and not before. Preservative-free versions are preferable if you are using something every night.

Moisture chamber goggles, sealing sleep masks and lid taping are all used for this, but only as your optometrist or ophthalmologist advises and demonstrates. Tape that lifts and contacts the cornea does more harm than the exposure did, and the skin under a nightly strip can react, which is why it is not a technique to work out from an article.

Small environmental changes help more than they sound like they should. Move the bedroom fan or air conditioning outlet so it is not blowing across your face, and consider a humidifier if your bedroom air is dry. If the cause is structural, an oculoplastic surgeon may be able to correct the lid position, and Latkany and colleagues note that correct and timely diagnosis also allows better planning for any future eye surgery.

Where tear volume is genuinely low, keeping the tears you have becomes an option. That is what punctal occlusion is for, and the trade-offs are set out in our article on punctal plugs. The DEWS II management report is a useful reality check on all of this: it derived a staged, step-wise algorithm according to disease severity, while being blunt that many available dry eye treatments lack the Level 1 evidence needed to support a firm recommendation.

The last point is the most important one. Nocturnal lagophthalmos is a mechanical problem with a mechanical cause, so lubricants manage the consequences while the cause goes unaddressed. Finding and treating the cause is the part that changes the trajectory.

When to be seen quickly

Some presentations are not a matter for the next routine appointment. New weakness on one side of the face, or a sudden inability to close one eye, needs medical attention the same day, because the eye is unprotected from that moment on. So does an eye that is becoming visibly more prominent, or new double vision.

For the eye itself, the warning signs are pain rather than irritation, marked light sensitivity, a white or grey patch on the cornea, discharge, or a drop in vision that does not clear when you blink. A contact lens wearer with a red eye should have the lens out and be seen urgently. If you have an eye infection, have had eye surgery recently, have glaucoma, or notice any change in your vision, speak to your optometrist or ophthalmologist before starting anything new, heat therapy included.

Frequently asked questions

Can you really sleep with your eyes open?

Yes. Nocturnal lagophthalmos is defined as the inability to close the eyelids during sleep, and the gap can be narrow enough that the eye looks shut. Latkany and colleagues also describe an obscure form in which the lids appear closed because the lashes obstruct the view or the upper lid overhangs the lower one, yet the eye is not actually sealed.

How do I know if I sleep with my eyes open?

Ask whoever sleeps near you to look, or to take a photograph once you have dropped off. The symptom pattern is the other clue: eyes at their worst on waking that improve through the day. An optometrist can usually settle it with a focused history and a slit lamp examination, looking for a residual gap and for surface damage along the lower cornea.

What helps with sleeping with your eyes open?

A thicker lubricating ointment at bedtime is the usual first step, since it stays on the exposed strip for hours. Moisture chamber goggles, sealing sleep masks and lid taping are all used for this, but only as your clinician advises and shows you, because badly applied tape can injure the cornea. Moving a fan away from your face and treating the underlying cause matter more than any drop.

Is nocturnal lagophthalmos serious?

Usually it is manageable, but it is not trivial, because it is associated with exposure keratopathy, poor sleep and persistent exposure-related symptoms. Seek attention the same day for new facial weakness, a sudden inability to close an eye, eye pain, a white patch on the cornea or a drop in vision that does not clear with blinking.

Educational information only, not medical advice. References: Latkany RL, et al. Ocul Surf. 2006;4:44–53; Bron AJ, et al. Ocul Surf. 2017;15:438–510; Jones L, et al. Ocul Surf. 2017;15:575–628.