The scientific concept of tears
The scientific concept of tears

Author - Karthiga Kanthan (Optometrist) 

Cry me a river...

Why is it that when a baby is born, a new parent sheds tears? Why is it that when a loved one moves on, we shed tears? When chopping onions to make your favourite dinner, why is it that we shed tears? What causes this process to occur and why does it happen?

Tears are a complex substance with a multipurpose role. It is produced in the lacrimal gland and secreted onto the anterior surface of the eye. It drains via the puncta, which are two small holes on the inner eyelid and seeps through the nose and hence when we cry usually we have a runny nose!

The eyes are an amazing organ which have the capacity to produce not one, not two but three types in the chemical composition of tears!  The basal tears are the type that is omnipresent. These tears lubricate the eye and hence contribute to ocular comfort. This tear layer is composed of three layers – lamina, aqueous and mucus which all serve a crucial function. The formation of these layers is quite a natural composition of tears. 

The second type of tears is the reflex tears. This is the type that makes your eyes water when you get an eyelash or any foreign body or vapour in your eye. It's the eye’s way of washing out the unwanted substance. This is the type of tears that are secreted when you chop onions!

The third type of tears called ‘psychic’ tears are released under intense emotion, stress or physical pain. Emotional stress triggers the nervous system which stimulates tear production. It is a biochemical response and hence after a good sob, stress hormones are released and consequently you feel better. Women are much better at producing psychic tears than men with the number of cries per year of women to men is 50:10!

Next time your lips quiver and you blink repeatedly in an attempt to prevent your tears, take a moment and contemplate your actions and try remembering the tear drops composition as given above, it may be worthwhile letting your tears all pour out‼


By Karthiga Kanthan

Optometrist at 1001 Optical. 

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