Crying or shedding tears is one way to express emotions. But behind his emotional impression, it turns out there are some interesting facts about tears that are not widely known.
Tears are produced by the lacrimal glands in the upper eyelid. In addition to venting emotions, it turns out tears also play an important role in maintaining eye health, such as to moisturize the eyes to prevent dry eyes and irritation, and provide nutrition to the eyes.
Tears Consist of Several Layers
Tears consist of three layers. Each tear layer contains various nutrients, such as potassium, sodium, protein, glucose and fat. These nutrients will later be used to protect and lubricate the surface of your eyes.
Here are the layers that are in tears:
A layer of water
This is the thickest layer in the structure of tears. The layer of water serves to remove impurities that enter the eye, moisturize the eye, and protect the cornea of the eye.
Oil coating
This layer contains more fat. This large amount of fat is useful for slowing evaporation on the surface of the eye.
Mucous layer
This layer is useful for coating the surface of the eye which will help tears stick to the eyes. Without this mucus layer, tears will appear to dry out like crust around the eyes.
Tears Are Produced Based on Their Functions and Causes
Although it looks the same, tears actually have several types, and their functions also vary. The types of tears are:
Basal tears
Basal tears are a type of tear that functions to protect and lubricate the eyes. Tears of this type are usually produced every day by the lacrimal glands, which keeps the eyes awake in moisture and avoid dry eyes and eye infections.
Reflex tears
This type of tear will be produced when the eye gets stimulation from outside the body which can cause irritation. For example when the eyes are exposed to dust, smoke, and when slicing onions. So, when the eye is irritated, the lacrimal glands will automatically produce these tears to protect and at the same time lubricate the eyes.
Tears of emotion
These tears generally form when you feel sad, moved, or happy. These tears contain stress hormones and painkillers, namely prolactin and enkephalin.
In the past, these emotional tears were thought to have no function. But now, some studies have found that emotional tears can help reduce stress and emotional distress, so it's natural that crying will make you feel better.
Some Causes of Reducing Tears
There are several conditions that can reduce tear production, including:
1. Aging
Old age is one of the risk factors for dry eye. This condition is more common in people aged over 50 years. Some research shows, tear production can be reduced in the elderly due to reduced amount of protein in tears and weakening of the function of the lacrimal gland.
2. Lacrimal gland infection (dacryoadenitis)
This condition can occur when viruses and bacteria infect the lacrimal glands, causing inflammation in these parts. This infection can reduce the function of the lacrimal glands in producing your tears.
3. Autoimmune diseases
Some autoimmune diseases can affect lacrimal glands in producing tears, such as rheumatoid arthritis, diabetes, lupus, scleroderma, and Sjögren's syndrome. In addition, several other diseases, such as thyroid hormone disorders, vitamin A deficiency, and blepharitis, can also inhibit tear production.
4. Side effects of drugs
Consumption of certain drugs can also affect the lacrimal glands in producing tears. Drugs that can reduce the function of the lacrimal gland include antihistamines, decongestants, antidepressant drugs, hypertension drugs, and birth control pills.
Because tears have an important function in maintaining eye health, their production needs to be maintained. If the eyes feel dry, you can use artificial tear drops.
If tear production is often problematic, you should consult an eye doctor for further examination and treatment.
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