“To weep is to make less the depth of grief.” ~ William Shakespeare
Crying is usually seen as something that we can’t help but do, without any consideration of how it could benefit us. We don’t decide to cry in order to receive a certain perk for example – yet it seems that there are indeed some positives behind shedding tears, and there are scientific studies to prove it.
Well we know that they are a salty fluid, but what actually makes up the stuff that we leak from our eyes. There are actually three different liquids in the film that covers our eyeballs, and each is made by a different gland. Dr Karl S. Kruszelnicki describes these in turn:
First, there is a mucous layer of tear film, resting immediately on your eyeball. It’s made by goblet cells in the conjunctiva (a membrane covering the whites of the eyeballs, and the inside of the eyelids). It’s specialised for sticking to, and coating, your eyeball closely and evenly.
The next layer of tear film is the aqueous layer. This liquid is made by the lacrimal gland (which I’ve already mentioned) in the upper outer corner of the eye socket. It’s mostly water, with various proteins, antibiotics and minerals. It protects your eyeball from bacteria, changes in temperature and saltiness, and so on.
The outermost layer is the lipid layer. This oily liquid is made by the meibomian (or tarsal) glands on the edges of your eyelids. This layer coats the watery layer underneath, and stops it from dribbling onto your cheeks, as well as slowing down its rate of evaporation.
Women tend to cry more than men – 47 times per year as opposed to 7 times per year on average. Each session lasts an average of 6 minutes, and some reports suggest that women cry a whopping 2 hours and 40 minutes each week – and a total of one year and four months during their lives.
Research has shown that we produce somewhere in the region of 10 ounces of tears every single day – which equates to 30 gallons a year!
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