"Why do our eyes water when we yawn?" According to popular opinion, it is because you are tired and you miss your bed, which is why you begin to tear up. Don't believe us? Well, you shouldn't.
As much as that rationale seems right (on an emotional level), there is complete science behind the question 'why do our eyes water when we yawn?'.
To understand this phenomenon, you will first need to understand tear-anatomy. Did you know there are three types of tears that your eyes shed?
1. Emotional Tears: Released upon experiencing intense emotions
2. Reflexive Tears: They serve to remove irritants and contaminants from the eyes like dust, dirt, etc.
3. Basal Tears: They are produced naturally throughout the day to lubricate the eyes.
Why do our eyes water when we yawn?
It is these basal tears that are responsible for the tears when you yawn.
Two components of the face are primarily responsible for our eyes to water when we yawn,
• Facial muscles
• Lacrimal glands
Lacrimal glands are glands that are placed beneath our upper eyelids just below the eyebrow bone.
They produce watery component to our eyes' own natural tears throughout the day to keep the surface of our eyes coated and moisturized. Thus, our eyes remain moist throughout the day because of the functioning of lacrimal glands (This is also the reason why our eyes look glossy)
There are 43 muscles in the face itself that work together to help us emote. When we yawn, the facial muscles around our eyes begin to tighten. This exerts pressure on the lacrimal glands and squeezes them a little.
In response, the lacrimal glands may release a little quantity of water which had been stored to release later.
Basal tears typically flow diagonally across the eyes and collect in a structure on the opposite corner of the eye called punctum.
But when we yawn, this water has no passage to get absorbed, and hence it falls out of the eyes, which is why it appears as if we are shedding tears.
Now if you shed a tear or two while yawning, don't feel like it's a 'miss you' call from your bed; it's just a natural reaction to feeling tired.
And if the next time somebody asks you, "why do our eyes water when we yawn?", don't shy away from sharing the knowledge!