Tears streaming down your face upon stepping into cold air is known as epiphora. This is a normal, protective response by the body to environmental stress. The cold and wind trigger a physiological chain of events designed to protect the highly sensitive surface of the eye by increasing tear production and managing fluid drainage.
The Reflexive Tear Response
The eye surface is densely innervated, containing specialized nerves highly sensitive to temperature changes and physical irritants. When cold air or wind strikes the cornea, it stimulates nerve endings that are part of the trigeminal nerve pathway. This sensory input sends a signal to the brain that the eye is under threat or is drying out.
To compensate, the brain initiates a protective response. This triggers the main lacrimal glands, located above the outer corner of the eyes, to rapidly secrete a large volume of fluid. These are known as reflex tears, which are chemically distinct from the basal tears that maintain constant lubrication. The quick flood of watery reflex tears washes away irritants and restores moisture to the eye’s surface.
Why Tears Overflow in the Cold
Tears spill onto the cheeks because the volume of reflex tears overwhelms the eye’s natural drainage capacity. The cold environment combines increased tear production with decreased tear removal. Tears normally drain through two small openings, called the puncta, located on the inner corners of the upper and lower eyelids.
From the puncta, tears flow into small tubes and eventually into the nasolacrimal duct, which empties into the nasal cavity. Cold temperatures and dry winter air can cause the mucous membranes lining the nose and the nasolacrimal duct to swell. This swelling physically narrows the drainage passage, creating a bottleneck for the increased tear volume.
Furthermore, the cold air causes tears to evaporate more quickly from the eye’s surface, which paradoxically signals the nerves to produce even more reflex tears. The drainage system is simply not designed to handle this high flow rate when the exit pathway is simultaneously constricted. The excess fluid has nowhere to go but to overflow the lower eyelid margin and run down the face.
Practical Steps to Reduce Watering
You can manage cold-induced watering by creating a physical barrier against the wind and cold. Wearing wrap-around sunglasses or goggles provides excellent protection, shielding the eye from direct air movement and reducing tear evaporation. Protective eyewear acts as a windbreak, lessening the stimulus for the reflex tear response.
Covering the lower half of your face with a scarf or neck gaiter can also help warm the air directly in front of your eyes. Indoors, dry air from central heating accelerates tear evaporation; using a humidifier to maintain indoor humidity between 30 and 50 percent is recommended. Applying preservative-free artificial tears before going outside can pre-moisten the eye surface, decreasing the initial reflexive need for tear overproduction.
When Watering Indicates a Health Problem
While cold-induced watering is generally harmless, persistent, excessive tearing (chronic epiphora) can signal an underlying health issue. If your eyes water consistently regardless of temperature or wind exposure, seek professional evaluation. A common, yet paradoxical, cause of chronic epiphora is dry eye syndrome, where poor tear film quality triggers an ineffective, constant reflexive overproduction of tears.
Other pathological causes involve a physical blockage in the drainage system, such as a nasolacrimal duct obstruction, which can occur due to infection, injury, or age-related narrowing. Signs that warrant a doctor’s visit include accompanying symptoms like eye pain, redness, blurred vision, or the presence of thick discharge. These symptoms may indicate an infection, such as dacryocystitis, or another condition requiring medical intervention.