We cry for all kinds of reasons: a stubbed toe, a particularly poignant scene in a movie, freshly cut onions — the list goes on.
Would it surprise you to learn that, chemically, not all tears are the same? Or how about that even though we usually do it when we’re upset, crying is actually good for us?
Tears And Basic Eye Protection
Even when we aren’t crying, our eyes are covered in a protective film of basal tears, which is composed of three layers: the mucous layer right up against the cornea, the middle aqueous layer that is mostly saltwater, and the outer lipid layer that seals everything in and reduces evaporation.
This tear film is essentially all-in-one lubrication, cleaning, and disinfecting system for the surface of our eyes. It washes debris like dust and other particles out of our eyes with every blink and keeps our eyes comfortable and our vision clear.
The lacrimal glands in our eyelids are constantly producing small amounts of basal tears to replenish the tear film. The reason our eyes don’t leak with used basal tears all day is that what doesn’t evaporate drains out through the lacrimal ducts on the inner corners of our eyes and down into our noses. That’s why our noses get runny when we cry!
Having A Good Cry
Basal tears are present all the time in healthy eyes, but when we cry and the tears overflow, they come in two different types: reflex and emotional tears. Even if crying can be embarrassing and messy at times, both types of tears are actually good for us.
Reflex tears are essentially the same as basal tears, but when our eyes get irritated, basal tear production goes into overdrive in an effort to safely flush out whatever caused the problem. That’s why we tear up when we’re chopping onions or get something in our eyes.
Most of us know what it’s like to cry and come out the other side of it feeling somehow refreshed and more optimistic about life, even when nothing about the situation that made us cry has actually changed. That’s because emotional tears actually clear out chemicals that build up in times of stress. Crying doesn’t just release pent-up emotion, it also purges harmful chemicals and triggers pain-regulating hormones! No wonder we feel better afterward!
Let’s Keep The Tears Flowing
Basal tears are essential for the health of our eyes, which is why dry eye can be such a serious issue. As we age, basal tear production goes down and dry eye becomes a more common problem. It can also be a side-effect of medication. Dry eye can lead significant discomfort, blurred vision, and even vision loss, so make sure you try to avoid it.
This post originally appeared on Vision Source.