When air enters the eye during nose blowing, it can be a surprising and unsettling experience. This phenomenon results from intricate connections within the head, specifically between the nasal passages and the eyes. Understanding the underlying anatomy and mechanics helps to clarify why this occurs.
The Anatomical Connection
The human body contains a specialized drainage system for tears, known as the nasolacrimal duct. This duct connects the inner corner of each eye to the nasal cavity. Tears collect at the medial angle of the eye, then enter small openings called puncta, which lead into canaliculi. These canaliculi drain into the lacrimal sac, which then continues as the nasolacrimal duct.
The nasolacrimal duct opens into the inferior meatus of the nasal cavity. A fold of tissue, known as the plica lacrimalis or valve of Hasner, partially covers this opening. The primary function of this system is to drain excess tears from the eye into the nose, which is why crying often leads to a runny nose.
Why Air Enters the Eye During Nose Blowing
The sensation of air entering the eye during nose blowing stems from a reversal of the normal tear drainage flow. When an individual blows their nose, particularly with force or if one or both nostrils are blocked, significant pressure builds within the nasal cavity. This pressure can become high enough to overcome the natural barrier provided by the valve of Hasner.
Once the pressure in the nasal cavity exceeds the resistance of the tear duct system, air is forced backward. This air travels up through the nasolacrimal duct and into the lacrimal sac, ultimately reaching the eye. This backward movement of air is often referred to as air reflux.
Is It Dangerous?
In most instances, experiencing air in the eye when blowing the nose is a harmless and benign occurrence, largely due to the normal anatomical connection. The sensation is temporary and resolves on its own. While generally not dangerous, rare complications can arise.
One rare complication is the potential for infection if nasal mucus, containing bacteria, is forced into the tear duct system and into the eye. Another serious concern is orbital emphysema, where air becomes trapped in the soft tissues around the eye. This typically occurs if there is an underlying defect or fracture in the thin bones separating the sinuses from the eye socket, which can be caused by facial trauma or forceful nose blowing. Symptoms of orbital emphysema can include swelling around the eye, bruising, or changes in vision, but most cases resolve without intervention.
Medical attention should be sought if there is:
Persistent pain
Noticeable swelling
Changes in vision such as blurriness or double vision
Signs of infection like redness or pus
The phenomenon occurs after a facial injury or surgery
Preventative Measures for Nose Blowing
To reduce the likelihood of air entering the eye when blowing the nose, individuals can adopt gentler techniques. Blowing the nose softly minimizes pressure buildup within the nasal cavity. Instead of forcefully blowing both nostrils simultaneously, blow one nostril at a time. This approach allows for more controlled pressure release and reduces force on nasal passages and connected structures.
Avoid pinching both nostrils completely closed during blowing, as this traps pressure and increases the chances of air reflux. If nasal passages are severely congested, attempting to blow forcefully may exacerbate the issue by creating excessive pressure. These methods help manage internal pressure and promote effective clearing of nasal passages without forcing air into unintended areas.