Tears play a crucial role in conveying our deepest emotions; in addition to their emotional significance, they are also scientifically important. Tears are not just an automatic reaction to sadness or joy, but rather they are evidence of the body's flexibility and ability to adapt to emotional or environmental changes. From each drop of tears, we can discover a special and different chemical language.
Tears are known as a salty watery fluid secreted by the tear glands in the eye. Tears are mainly made of 98% of water, while the remaining 2% contain complex chemical compounds that give tears their unique and distinctive properties, such as electrolytes, enzymes, proteins, and fats.
Tears are not limited to one type, but rather vary according to the reason that led to their secretion. They can be classified into three main types:
- Basal tears: tears that are secreted continuously to keep the eye moist and protect it from dryness and dust. These tears play a pivotal role in eye health.
- Reflex tears: these tears are secreted in response to an external stimulus, such as a foreign body entering the eye or the exposure to smoke or onion fumes. Mainly, these tears are responsible for expelling the irritants and protect the eye.
- Emotional tears: are the tears that are related to our feelings and emotions, whether happiness, sadness, or anger. This type of tears is the most chemically complex tears.
The chemical composition of tears varies according to the type and cause of tears; for example, basal tears contain water, electrolytes (such as sodium, potassium, and chloride ions), and proteins, such as lysozyme, lactoferrin, and lipocalin, which help fight microbes and foreign bodies, and maintain eye health. Reflex tears contain additional components, including antibodies called immunoglobulin, enzymes, and lipids, which help remove irritants and promote healing.
Emotional tears contain higher amounts of stress hormones, such as cortisol and adrenaline, which may help relieve emotional distress. They also contain neurotransmitters, such as endorphins, which act as natural pain killers and mood enhancers. Moreover, these tears contain high levels of manganese, which is the element that contributes to relieving stress.
Chemical analysis of tears has also proven its importance in the field of medical diagnostics; scientists have discovered tear analysis as a potential non-surgical diagnostic tool for certain conditions. For example, tears biomarkers have been tested to detect certain eye diseases, such as dry eye syndrome, glaucoma, and even diabetes, by analyzing the levels of certain molecules in tears. The researchers aim to develop tear analysis as a convenient, cost-effective, and less invasive diagnostic tool than traditional methods.
Some people have always wondered why we cry, and what is the benefit of releasing these water drops from the eye. Studies indicate that crying can be a mechanism to get rid of harmful chemicals that accumulate in the body as a result of stress and psychological stress. Crying also helps relieve psychological and emotional pain, and enhances feelings of comfort and relieves stress. Crying also helps people sleep, specially children. A 2014 study found that crying may have a calming effect. The study showed how crying activates the parasympathetic nervous system (PNS), which helps people relax.
Studying the chemistry of tears opens new horizons for understanding the nature of the human body and its complex interactions. In each drop of tears lies a scientific mystery waiting for us to decipher its code, perhaps in the near future. These studies will help us develop new treatments and diagnostics for some diseases, or even understand the origins of human emotions more deeply.
References
brighterkashmir.com
news-medical.net
medicalnewstoday.com