The sight of a child sleeping with their eyes partially open can be unsettling for any parent. This phenomenon is often observed when a child is unwell, making the experience doubly alarming. While illness seems unrelated to eyelid function, the physiological changes that accompany sickness can intensify a pre-existing, usually harmless, sleep pattern. Understanding how a temporary sickness disrupts sleep mechanics can provide clarity and guidance on how to best care for your child.
Why Some Children Sleep With Their Eyes Open
The technical term for sleeping with eyes incompletely closed is nocturnal lagophthalmos, a condition that occurs in a significant portion of the general population. This behavior is often benign and may be an inherited trait, sometimes running in families. The eyelids are typically functional and close fully when the person is awake and blinking.
The incomplete closure is often linked to the mechanics of the sleep cycle, particularly during the rapid eye movement (REM) phase. During REM sleep, the brain is highly active, but the body experiences a temporary paralysis of major muscle groups, known as atonia. The muscles controlling the eyelids can sometimes fail to fully engage the closing mechanism, leaving a small gap.
Estimates suggest that up to 20% of the population, including many infants, may experience some degree of nocturnal lagophthalmos. In most cases, the eyes naturally roll back during sleep, a protective reflex that shields the cornea. Since the condition often causes no symptoms, it frequently goes undiagnosed until observed by a parent or partner.
How Illness Affects Eyelid Closure
When a child is sick, the body’s response to infection disrupts normal sleep architecture and muscle function, making pre-existing lagophthalmos more noticeable. Fever can alter sleep cycles, causing fragmented and shallow rest periods. This disruption interferes with the brain’s signals that regulate muscle tone during sleep, potentially worsening the incomplete eyelid closure.
Nasal congestion from a cold or flu also plays a role by forcing the child to breathe through their mouth. This mouth-breathing can lead to a general relaxation of the jaw and facial muscles, making the partial opening of the eyelids more pronounced.
Dehydration, a common side effect of fever and reduced fluid intake, can also indirectly affect the eyes. A lack of adequate hydration reduces the body’s natural tear production, making the eyes more susceptible to dryness from exposure. The sickness does not cause lagophthalmos but rather exacerbates the underlying, usually mild, phenomenon.
Protecting the Eyes from Dryness and Irritation
The main concern when the eyes are partially open during sleep is the risk of excessive dryness, as the tear film evaporates quickly when exposed to air. This constant exposure can lead to irritation, redness, and a gritty feeling upon waking. There are several simple, at-home measures to mitigate this effect and protect the ocular surface.
The most direct care involves using over-the-counter lubricating eye drops, also known as artificial tears, or ophthalmic lubricating gels. These products are applied directly to the eye before sleep to provide a protective layer of moisture that supplements natural tears. The gels or ointments tend to be thicker and last longer, offering extended protection throughout the night.
Another strategy is to increase the humidity in the child’s bedroom using a cool-mist humidifier. Increasing the moisture content in the air helps slow the evaporation rate of the tear film from the exposed eye surface. Parents should also ensure the child’s bed is not positioned directly in the path of a fan or air conditioning vent, which can hasten tear evaporation.
Signs That Require Medical Attention
While nocturnal lagophthalmos is often a temporary, harmless issue associated with a short-term illness, certain signs warrant a medical consultation. Any persistent redness, swelling, or discharge from the eye, particularly if it is thick or yellowish, suggests a possible infection requiring treatment. Symptoms that worsen instead of improving as the illness resolves should also be evaluated.
You should seek medical advice if your child complains of pain, a constant foreign body sensation, or noticeable changes in vision, such as blurriness. These symptoms can indicate damage to the cornea. A doctor should also assess any accompanying signs of nerve or muscle weakness, such as facial drooping or an inability to voluntarily close the eye fully while awake.
If the eye-opening behavior continues long after the child has recovered from their illness or if the gap between the eyelids is very wide, an eye specialist can perform a detailed examination. They will assess the extent of the closure issue and check the health of the cornea to prevent long-term complications. A thorough evaluation ensures the condition is truly benign and not a symptom of a more complex underlying issue.