Tears are needed to help you see clearly and maintain the health of your eyes. Aside the medical benefits, they help communicate your emotions, especially when one is sad or overly excited. The human body makes three types of tears. The types includes:
This type of tears are in the eyes all the time to lubricate, nourish and protect your cornea. The cornea is the clear, dome-shaped window of the front of your eye.
Basal tears acts as a continual shield between the eye and the rest of the world, keeping dirt and debris away.
This form of tears are formed when the eyes need to wash away harmful irritants, such as smoke, foreign body or onion fumes.
Your eye release them in large amount than the basal tears, and they may contain more antibodies to help fight bacteria. Here, the inflammation process may be initiated, where redness, pain and swelling is more paramount.
This kind of tears are produced in the response to joy, sadness, fear, and other emotional states.
According to research, scientists have proposed that emotional tears contain additional hormones and proteins not present in basal or reflex tears. Stress hormones such as cortisol, adrenalin and norepinephrine are highly released in this tears.
Emotionally triggered-tear production also releases endorphins and oxytocin which are natural pain relievers.
This explains why headaches that occur as a result of crying for a longer period of time which is clearly induced by emotions, subsides on it own without the use if analgesics (pain killers).
DID YOU KNOW TEARS HAVE LAYERS
Tears are not just saline(water), they also contain enzymes (lysozyme), lipids, metabolites (mucin) and electrolytes (sodium, potassium, chloride etc).
Each tear has three layers
- The outer oily layer (LIPID LAYER) to keep the surface smooth for the eye to see through and to prevent the other layers from evaporating.
- A watery middle layer (AQUEOUS LAYER) the thickest layer helps keep the eye hydrated, repel bacteria and protect the cornea.
- An inner mucus (MUCOUS LAYER) layer that keeps the whole tear fastened to the eye.
Lacrimal gland located above each eye produce tears. As you blink, tears spread across the surface of the eye. Then the tears drain into puncta (upper and lower punctum), the tiny holes in the corners of your upper and lower eyelids.
The tears then travel through small canals in the eyelids (upper and lower canaliculus) and down a duct before emptying into your nose.
There, tears will either evaporate or be absorbed. There is a duct called the nasolacrimal duct –this is also known as the tear duct), it transfers tears from the lacrimal sac (it is the upper dilated end of the nasolacrimal duct) of the eye into the nasal cavity.
Babies are sometimes born with a blocked tear duct, this condition usually resolves on it own. In adult, the tear duct can be blocked by an eye infection, swelling, injury or a tumor.
When a lot of emotional or reflex tears are made, they overwhelm the lacrimal drainage system.
That’s why these tears can spill out of your eyes, run down your cheeks and sometimes dribble out of your nose.