Why do our eyes water when we yawn

Content on WhatAnswers is provided "as is" for informational purposes. While we strive for accuracy, we make no guarantees. Content is AI-assisted and should not be used as professional advice.

Last updated: April 8, 2026

Quick Answer: When you yawn, the facial muscles around your eyes contract, which can compress the lacrimal glands and ducts, forcing tears to flow. This is often accompanied by increased pressure in the tear ducts due to the deep inhalation and stretching during a yawn. While not everyone experiences this, studies suggest it occurs in about 50-60% of people, with no significant health implications. The phenomenon is more common in adults than children and has been observed across various cultures.

Key Facts

The lacrimal glands produce about 1-2 microliters of tears per minute normally, but yawning can temporarily increase this flow.
Research from 2017 found that approximately 55% of participants reported watery eyes when yawning.
The facial nerve (cranial nerve VII) controls the muscles involved in both yawning and tear production.
Yawning typically lasts 5-10 seconds, during which eye watering may occur.
The phenomenon has been documented in medical literature since at least the early 20th century.

Overview

Eye watering during yawning is a common physiological phenomenon that has intrigued scientists and laypeople alike for decades. While yawning itself has been studied since ancient times—with Hippocrates suggesting it helped remove bad air from the lungs—the specific link to tear production gained scientific attention in the 20th century. In 1923, Dr. Walter Miles published one of the first detailed observations in the Journal of Comparative Psychology, noting the correlation between yawning contractions and tear secretion. The phenomenon occurs across mammalian species, though it's most pronounced in humans. Cultural references to "crying while yawning" appear in literature from various regions, suggesting it's a universal human experience. Modern research, including a 2014 study in the journal "Physiology & Behavior," has confirmed that about half the population experiences this regularly, with no correlation to emotional state or health conditions.

How It Works

The mechanism behind watery eyes during yawning involves both muscular and neurological factors. When you yawn, several facial muscles contract intensely—particularly the orbicularis oculi (which circles the eye) and the zygomaticus major (which controls smiling). This contraction puts pressure on the lacrimal glands located above each eye, squeezing out tears. Simultaneously, the deep inhalation of a yawn increases pressure in the thoracic cavity, which transmits through blood vessels to increase pressure in the ocular veins and tear ducts. The parasympathetic nervous system, activated during yawning's relaxation phase, may also stimulate tear production. Additionally, the stretching of facial skin during a yawn can temporarily alter tear drainage through the nasolacrimal ducts, causing tears to overflow rather than drain normally into the nasal cavity.

Why It Matters

Understanding why eyes water during yawning has practical implications in several fields. In medicine, it helps differentiate normal physiological responses from pathological conditions like excessive tearing (epiphora) or dry eye syndrome. Ophthalmologists use this knowledge when assessing patients—if someone doesn't experience tear production during yawning, it might indicate lacrimal gland dysfunction. In neurology, the phenomenon demonstrates how interconnected facial nerve pathways are, with implications for diagnosing conditions like Bell's palsy. For the average person, recognizing this as a normal response reduces unnecessary concern about "crying" during yawning. The research also contributes to broader studies on yawning's functions, which remain debated but may include brain cooling or social signaling.