Wednesday November 13, 2019

Why do Our Eyes Water when We Yawn?

Did you know there are three different types of tears that our eyes shed?

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why do our eyes water when we yawn
Teary-eyed after a yawn? We will tell you why! Pixabay

“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.
 
But our question was :

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!

Next Story

Researchers Find Cells Linked to Blindness in Elderly People

This study helps pinpoint cell types that can be investigated closely to develop new types of therapeutics

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Bindness
Age-related macular degeneration is one of the leading causes of Blindness in the elderly. Pixabay

A team of researchers have discovered cells that lead to progressive loss of central vision among the elderly.

Age-related macular degeneration is one of the leading causes of blindness in the elderly.

Genome-wide studies have identified almost three dozen genes that play a role in the disease, but exactly where in the eye they inflict damage was not well known.

Researchers from Yale University, the Broad Institute of the Massachusetts Institute of Technology, and Harvard University reported in the journal Nature Communications that glial cells (or support cells), and vasculature cells tasked with providing blood to the retina as well as cone cells contribute to degeneration of the macula, in the central part of the retina.

“This study helps pinpoint cell types that can be investigated closely to develop new types of therapeutics,” said Brian Hafler, assistant professor of ophthalmology and visual science and of pathology at Yale.

There are a limited number of effective long-term treatments available for the two forms of macular degeneration.

The wet form is caused by growth of abnormal blood vessels underneath the macula, which can be mitigated by regular injections in the eye.

Blindness
While genes associated with the risk of developing macular degeneration had been identified, the team used new single-cell sequencing to generate the first comprehensive human retinal atlas and employed data analysis technology to localize their effects to specific cell types associated with Blindness. Pixabay

Other than eye vitamin supplements, there is no treatment for the dry form of the disease, which is marked by accumulations of yellow deposits called drusen in the macula.

While current treatments provide some benefits, over time there can be a continued, progressive loss of vision in both forms of the disease.

While genes associated with the risk of developing macular degeneration had been identified, the team used new single-cell sequencing to generate the first comprehensive human retinal atlas and employed data analysis technology to localize their effects to specific cell types associated with the disease.

ALSO READ: Young Mothers Likely to Have Kids with ADHD: Study

While they found risk genes associated with cones, the cell type key to central vision, the researchers also found an association with glial and vascular cells — providing possible targets for novel therapies to improve and restore vision. (IANS)