The experience of tears unexpectedly pooling or running down the face when lying down is a common and often confusing form of excessive tearing, medically known as epiphora. This condition arises from an imbalance between the production of tears and their drainage, essentially a plumbing issue in the eye’s tear system. While tears are essential for lubricating the eye and washing away debris, when the system fails, the overflow can be a significant nuisance, causing temporary blurred vision and skin irritation. Understanding the physical mechanics of tear drainage helps explain why this overflow is particularly noticeable when the body shifts from a vertical to a horizontal position.
Why Gravity Matters for Tear Flow
The tear drainage system, or lacrimal system, relies on both active and passive mechanisms to clear fluid from the eye surface. Tears are produced by the lacrimal glands and collect near the inner corner. They then drain through two tiny openings called puncta, located on the upper and lower eyelids, leading into the canaliculi, the lacrimal sac, and finally down the nasolacrimal duct into the nasal cavity.
The active part of drainage is the lacrimal pump, powered by the blinking action of the eyelids. When we blink, the muscles around the eye compress the tear sac, creating a negative pressure that actively sucks tears into the drainage ducts. The passive component of this system is gravity, which helps guide the tears toward the puncta when a person is standing or sitting upright.
When you lie down, you minimize the assistance of gravity, and the passive drainage mechanism is significantly reduced. Furthermore, blinking may become less frequent, and the pumping action less effective, especially during sleep or deep relaxation. This combination means that even a normal volume of tears can pool at the eye’s margin, eventually overflowing onto the cheek because the horizontal ducts cannot handle the fluid without gravitational aid.
Underlying Issues Causing Epiphora
When tearing while horizontal becomes a persistent problem, it often points to an underlying issue that compromises the tear drainage system’s efficiency. These causes generally fall into two categories: drainage failure and reflex tear overproduction. Drainage failure occurs when there is a physical obstruction or narrowing anywhere along the tear duct pathway.
Narrowing of the puncta (punctal stenosis) or a blockage within the nasolacrimal duct are common culprits, especially in adults over 50. Tears cannot move through the system fast enough, and the backlog causes overflow. Chronic inflammation or scarring from previous infections, such as dacryocystitis, can also lead to acquired blockages in the drainage channels.
In contrast, reflex tear overproduction occurs when the eye produces excessive tears in response to irritation, overwhelming a functional drainage system. Paradoxically, the most common trigger is Dry Eye Syndrome, where the tear film is unstable or poor quality. Surface irritation triggers the main lacrimal gland to produce watery, reflex tears, which the ducts cannot handle.
Lying down may increase exposure to environmental irritants, exacerbating reflex tearing. Dust mites, pet dander, or residual makeup can irritate the ocular surface, especially when the face is pressed against a pillow. Allergies and certain eyelid abnormalities, such as an outward-turning lower eyelid (ectropion), can also prevent the puncta from making proper contact with the tear pool, leading to drainage issues and overflow.
Immediate Steps for Symptom Relief
For temporary or mild tearing when lying down, simple hygiene and environmental adjustments can provide immediate relief. Proper eyelid hygiene is important, especially if irritation from debris or inflammation is suspected. Applying a warm, damp compress to the closed eyelids for five to ten minutes can help loosen blockages and improve oil gland function, stabilizing the tear film.
If the tearing is suspected to be a reaction to dryness, using preservative-free artificial tears can soothe the ocular surface and reduce the need for reflex tearing. These drops should be used before lying down to ensure the eye is adequately lubricated. Adjusting the sleeping environment, such as using a humidifier, can also minimize the dryness that triggers the overproduction of tears.
Minimizing exposure to irritants involves changing pillowcases frequently or avoiding fans that blow directly onto the face. For side sleepers, slightly elevating the head can restore a minor gravitational advantage to tear drainage, helping tears move more efficiently toward the inner corner. Thorough removal of eye makeup before bed also reduces the chance of debris irritating the eye surface overnight.
Signs That Require Medical Attention
While occasional watering when horizontal may be positional, persistent or worsening epiphora warrants professional evaluation by an optometrist or ophthalmologist. Certain accompanying symptoms serve as red flags indicating a more serious underlying condition. These include any new pain, swelling, or redness around the eye, particularly near the inner corner.
The presence of a thick, sticky discharge or pus, especially alongside tearing, suggests an infection such as dacryocystitis, which requires antibiotic treatment. A sudden change in vision or blurred vision that does not clear with blinking is also a sign that immediate medical attention is needed. Unilateral tearing, meaning only one eye is affected, often points toward a localized issue like a blocked tear duct or a foreign body, rather than a systemic cause like allergies.
An eye care specialist can perform diagnostic tests, such as staining tears with a fluorescent dye to track drainage speed, determining if the issue is tear overproduction or a physical blockage. Interventions range from prescription eye drops for inflammation to in-office procedures like probing and irrigation to clear a partially blocked duct. For complete obstructions, minor surgical procedures, such as dacryocystorhinostomy (DCR), may be necessary to create a new drainage pathway.