Why Some People Sleep With Their Eyes Open (Nocturnal Lagophthalmos)

Sleep is an essential function that allows the body and mind to recharge, but for some individuals, the process is not as straightforward as simply closing their eyes. A small percentage of people experience a peculiar condition known as nocturnal lagophthalmos, which prevents them from fully closing their eyelids while sleeping. This unusual phenomenon can lead to discomfort, dryness, and even long-term complications if left untreated.

Understanding why some people sleep with their eyes open requires an exploration of its causes, symptoms, potential risks, and available treatments. This article delves into the science behind nocturnal lagophthalmos, shedding light on its underlying mechanisms and how individuals can manage the condition effectively.

What Is Nocturnal Lagophthalmos?

Nocturnal lagophthalmos is a condition where a person’s eyelids do not fully close during sleep. This partial closure or complete inability to shut the eyes can result in eye exposure to air and environmental elements, leading to irritation, dryness, and a higher risk of infections.

The term "lagophthalmos" originates from the Greek word "lagos," meaning "hare," since ancient observers noted that hares often sleep with their eyes partially open. While the condition may not always be severe, chronic cases can lead to more serious complications, such as corneal ulcers and vision impairment.

How Common Is It?

Research suggests that nocturnal lagophthalmos affects approximately 5% to 20% of the population to some degree. 

While the condition can affect individuals of any age, it is more commonly reported in people with nerve damage, facial trauma, or underlying medical conditions that affect muscle control.

Causes of Sleeping With Eyes Open

Sleeping with eyes open, known as nocturnal lagophthalmos, can result from various factors that affect the eyelid’s ability to close completely. 

These causes range from nerve damage and muscle weakness to medical conditions that alter eyelid function. Below are some of the primary reasons why people experience this condition.

Facial Nerve Damage or Paralysis

One of the most common causes of nocturnal lagophthalmos is damage to the facial nerve (cranial nerve VII), which controls the muscles responsible for closing the eyelids. If this nerve is weakened or injured, the eyelids may not fully shut during sleep. This type of nerve damage can occur due to conditions like Bell’s palsy, which causes temporary facial paralysis, or stroke, which affects muscle control.

Additionally, surgical procedures, head injuries, or trauma to the face can lead to nerve dysfunction, making it difficult to close the eyes completely.

Weak or Dysfunctional Eyelid Muscles

The eyelids rely on orbicularis oculi muscles to close properly. If these muscles are weak or dysfunctional, full eyelid closure may be impossible. 

This weakness can be due to aging, as the muscles lose strength over time, or neuromuscular disorders like myasthenia gravis, which affect the way muscles respond to nerve signals. In some cases, congenital conditions present from birth can cause eyelid abnormalities, leading to incomplete closure during sleep.

Thyroid Eye Disease (Graves’ Ophthalmopathy)

People with thyroid disorders, especially Graves’ disease, may develop proptosis, a condition where the eyes protrude forward. This forward displacement of the eyeball can prevent the eyelids from closing completely. 

Additionally, thyroid eye disease can cause eyelid retraction, where the upper eyelid remains abnormally high, making it difficult to fully shut the eyes. This often leads to excessive dryness, irritation, and an increased risk of corneal exposure during sleep.

Sleep Disorders and Abnormal Sleep Patterns

Certain sleep disorders can contribute to nocturnal lagophthalmos. REM sleep behavior disorder (RBD), for example, causes people to move excessively during sleep, sometimes preventing their eyelids from closing properly.

Additionally, individuals who experience high stress and anxiety may have increased muscle tension, which can interfere with normal eyelid closure. Sleep apnea, a condition where breathing repeatedly stops and starts during sleep, has also been associated with incomplete eyelid closure in some cases.

Post-Surgical Effects

Cosmetic or reconstructive eyelid surgery, such as blepharoplasty (eyelid lift), can sometimes lead to nocturnal lagophthalmos if too much skin is removed or if the natural muscle function is altered. 

Patients who have undergone facial nerve or eye-related surgeries may also experience changes in their ability to close their eyelids completely. While some cases improve with time, others may require corrective procedures to restore proper eyelid closure.

Genetic or Congenital Factors

Some individuals are born with anatomical differences in their eyelid structure that make it difficult to close their eyes fully. A family history of nocturnal lagophthalmos can increase the likelihood of experiencing the condition. In these cases, the issue is often present from childhood, though symptoms may become more noticeable as the individual grows older.

Sleeping with eyes open can stem from a variety of causes, ranging from medical conditions to nerve and muscle dysfunction. Identifying the underlying reason for nocturnal lagophthalmos is essential for finding the right treatment and preventing long-term complications.

Symptoms of Sleeping With Eyes Open

Eye Dryness and Irritation

One of the most common symptoms of sleeping with eyes open is excessive dryness. Since the eyelids are unable to fully close, the eye’s surface is exposed to air for prolonged periods, leading to rapid tear evaporation. 

This can result in irritation, making the eyes feel gritty, scratchy, or uncomfortable, especially upon waking. Many individuals describe a sensation similar to having sand in their eyes, which can persist throughout the day.

Red or Bloodshot Eyes

Chronic exposure to air and dust can cause inflammation in the blood vessels of the eyes, leading to a red or bloodshot appearance. 

This redness may be mild in some cases but can become more pronounced if the eyes remain irritated for long periods. Over time, frequent inflammation can increase sensitivity and discomfort, making it difficult for individuals to keep their eyes open comfortably during the day.

Burning or Itching Sensation

People with nocturnal lagophthalmos often experience a persistent burning or itching sensation in their eyes. This occurs due to inadequate moisture and irritation of the corneal surface. 

Rubbing the eyes may provide temporary relief, but it can worsen the problem by further irritating the delicate tissues or introducing bacteria, increasing the risk of infections.

Blurred or Fluctuating Vision

Another noticeable symptom is blurred vision, which is often most prominent in the morning. The lack of adequate moisture can cause the cornea to dry out, temporarily affecting the clarity of vision.

Some individuals may experience fluctuating vision throughout the day, particularly if their eyes struggle to maintain sufficient lubrication. In severe cases, corneal damage can lead to more persistent visual disturbances.

Sensitivity to Light (Photophobia)

Since the eyes are not fully protected during sleep, they can become more sensitive to light over time. Individuals with nocturnal lagophthalmos may find bright lights or sudden exposure to sunlight particularly uncomfortable.

This heightened sensitivity can make daily activities, such as driving or working on screens, more challenging and may contribute to frequent eye strain.

Frequent Eye Infections

Sleeping with eyes partially open increases the risk of infections because the natural protective barrier of the eyelids is compromised.

 Without complete closure, bacteria and environmental irritants can enter the eyes more easily, leading to conditions like conjunctivitis (pink eye). Symptoms such as excessive tearing, pus discharge, and swelling of the eyelids may indicate an underlying infection that requires medical attention.

Eye Pain or Soreness

Many individuals with nocturnal lagophthalmos wake up with eye pain or general soreness. This discomfort often worsens as the condition progresses, particularly if the cornea becomes irritated or damaged. The pain may be dull and persistent or sharp in cases where the cornea develops small abrasions due to dryness and friction with the eyelids.

Tired or Heavy Eyes Upon Waking

People with nocturnal lagophthalmos often wake up feeling as though their eyes are heavy, strained, or not fully rested. 

This is because the eyes are working harder throughout the night to compensate for the lack of protection. In some cases, individuals may also experience morning headaches or an overall sense of fatigue due to disrupted sleep quality.

Worsening Symptoms Over Time

Without proper treatment, the symptoms of sleeping with eyes open can progressively worsen. Chronic dryness can lead to long-term damage to the cornea, increasing the risk of scarring, ulcers, and even vision loss in severe cases. If symptoms persist or intensify, seeking medical advice is essential to prevent complications and protect eye health.

How Is Nocturnal Lagophthalmos Diagnosed?

A doctor or ophthalmologist can diagnose nocturnal lagophthalmos through a combination of patient history, physical examination, and eye tests. Some common diagnostic approaches include:

Eyelid closure assessment – The doctor observes how completely the eyelids close during sleep or when instructed to blink slowly.

Slit-lamp examination – A special microscope is used to examine the cornea for signs of dryness, damage, or ulceration.

Fluorescein staining – A dye test that highlights areas of damage or dryness on the eye’s surface.

Treatment Options

Fortunately, there are several treatment options for managing nocturnal lagophthalmos. The appropriate treatment depends on the severity of the condition and its underlying cause.

1. Conservative Treatments

For mild cases, simple interventions may help protect the eyes:

▪︎Artificial tears and lubricating ointments – These help keep the eyes moist throughout the night.

▪︎Moisture goggles – Special protective goggles or eye masks create a humid environment to prevent excessive dryness.

▪︎Taping the eyelids shut – Medical tape can be used to gently keep the eyelids closed during sleep.

▪︎Using a humidifier – Adding moisture to the air in the bedroom can reduce eye dryness.

2. Medical Treatments

If conservative measures do not provide relief, medical interventions may be necessary:

▪︎Eyelid weight implants – Small gold or platinum weights can be inserted into the upper eyelid to assist with full closure.

▪︎Surgical correction – Procedures such as tarsorrhaphy (partially sewing the eyelids together) or eyelid reconstruction can help restore normal function.

3. Addressing Underlying Conditions

If nocturnal lagophthalmos is caused by an underlying issue such as thyroid disease, facial nerve paralysis, or post-surgical effects, treating the root cause can often alleviate the condition.

Conclusion

Nocturnal lagophthalmos, or sleeping with eyes open, may seem like an unusual and harmless condition, but it can have significant consequences if left unmanaged. While some individuals may experience only mild symptoms, others face discomfort, chronic dryness, and potential vision complications.

Fortunately, various treatment options—from simple moisture-retaining methods to surgical interventions—can help individuals manage and improve their eye health. If you or someone you know experiences symptoms of nocturnal lagophthalmos, seeking medical advice can ensure proper care and prevent long-term damage.

By understanding the causes, risks, and treatment approaches, those affected can take proactive steps to protect their vision and improve their sleep quality.