The sensation of feeling a “cold liquid coming out of the eyes” describes excessive tearing, a condition formally known as epiphora. This feeling is not due to a sudden drop in the tear fluid’s temperature inside the eye. Instead, it results from the fluid overwhelming the eye’s natural drainage system and spilling onto the surrounding skin. When this excess fluid, composed primarily of water and saline, pools and runs down the cheek, it cools rapidly, causing the cold sensation.
The Science Behind the Cold Sensation
The cooling sensation is rooted in the physics of heat transfer, specifically a process called evaporative cooling. Tears are secreted by the lacrimal glands at body temperature, approximately 98.6°F (37°C). Once the fluid exits the eye and spreads across the skin, it is exposed to ambient air. The liquid quickly begins to convert to a gas, a process that requires thermal energy. The tears draw this necessary energy directly from the skin and the remaining liquid, causing a localized drop in temperature. Since tears are mostly water, they evaporate rapidly, creating a noticeable chilling effect on the skin as the warmth is carried away with the water vapor.
Triggers for Tear Overproduction
The primary reason for the cold sensation is the overproduction of tear fluid, which is often a protective reflex. The eye responds physiologically to environmental stressors like wind, cold air, or dry conditions. When the delicate ocular surface dries out, the lacrimal gland is stimulated to produce a flood of reflex tears to prevent surface damage. This paradoxical tearing—where a dry environment causes watery eyes—is a frequent cause of overflow.
Irritants like dust, smoke, or certain chemicals also trigger this defensive reflex, causing the production of large volumes of tears intended to flush the foreign substance from the eye. These reflex tears can sometimes contain higher concentrations of salt and antibodies. Allergies are another significant factor, as the release of histamine causes inflammation and prompts the eye to produce excessive fluid. Furthermore, a common cold or flu can cause watery eyes due to inflammation and swelling within the nasal passages. This swelling physically obstructs the normal drainage route for tears, causing them to back up and overflow.
How the Tear Drainage System Works
Tears are continuously produced to nourish and protect the eye, but the drainage system normally prevents them from spilling over. This “plumbing” system begins with two tiny openings called puncta, located on the inner edge of the upper and lower eyelids near the nose. From the puncta, tears travel into small tubes called canaliculi, which merge into a common channel before emptying into the lacrimal sac, a small reservoir nestled in the facial bones.
The lacrimal sac connects to the nasolacrimal duct, which descends through the bone structure and opens into the nasal cavity. This entire system allows tears to drain into the nose and throat, which is why crying often leads to a runny nose. When any part of this narrow pathway becomes blocked or constricted—such as from swelling due to a cold, chronic inflammation, or anatomical narrowing (stenosis)—the tears have nowhere to go but out and over the eyelid margin, resulting in epiphora.
When to Consult a Healthcare Professional
While occasional watery eyes due to environmental triggers or mild illness are normal, persistent, non-resolving epiphora should be examined by an optometrist or ophthalmologist. A blockage in the drainage system or chronic dry eye, which causes reflex tearing, may require specific treatment. Prompt medical attention is necessary if the excessive tearing is accompanied by specific symptoms that suggest a more serious underlying condition, such as:
- Significant eye pain.
- Noticeable changes in vision.
- Extreme redness in the white of the eye.
- Thick, yellow, or green discharge, which often signals a bacterial infection requiring prescription medication.