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Tears are present in the eyes from birth and throughout life
Tears are present in the eyes from birth and throughout life, provided there are no other medical conditions that prevent tear formation. Tear production tends to decrease as a part of the aging process. Humans produce 30 gallons of tears a year. The main function of tears is to clean, protect, and lubricate the eyes. Tears also have antibacterial properties. Tears are essential to maintain healthy eyes.
Tears have a similar composition to saliva, which is mostly water. Tears contain salt, fatty oils, glucose, lysozyme, and over 1500 proteins. Tears also contain electrolytes, such as sodium, bicarbonate, chloride, potassium, and small amounts of magnesium and calcium. Tears are secreted from the lacrimal glands located in the corner of the upper eyelid. The tears move from the outer edge of the eyeball towards the cornea and lubricate the entire eye while blinking. Tears can overflow and roll down the sides of our cheeks. Sometimes, the tear ducts don’t produce enough quantity of tears and/or good quality tears to keep eyes adequately lubricated, clear, and healthy. Having dry eyes requires medical attention to diagnose its cause and receive appropriate treatment.
There are three types of tears: basal tears, reflex tears, and emotional tears. They vary in composition drastically.
The following are characteristics of the three types of tears:
- Basal tears:
Basal tears are basic functional tears. They are continuously released in small quantities to clear the cornea and keep the eyes lubricated. They also have antibacterial properties. Basal tears are essential to ensure good vision, as well as healthy and comfortable eyes. Too much screen time, exposure to wind while driving a bike, and certain acne medications can reduce basal tear production and cause dry eyes.
- Reflex tears:
Reflex tears are also called irritant tears. They occur because of irritation of the eyes. This could be due to foreign particles, irritant chemical fumes, pepper spray, strong fragrances, tear gas smoke, bright lights, or chopping onions. They may also occur due to eating spicy food, vomiting, coughing, yawning, or prolonged screen time. Irritant tears may also be associated with redness of the eyes. Reflex tears are usually released in larger quantities than basal tears. The purpose of reflex tears is mainly protecting and clearing the eyes.
- Emotional tears:
Emotional tears are also called psychic tears. They are referred to as crying or weeping. These tears are associated with all emotions. They are triggered due to emotional stress, anger, sadness, physical pain, or even extreme happiness (happy tears) and laughing. They are not always associated with negative emotions. Emotional tears are produced to stabilize the mood as quickly as possible. Therefore, many people often feel better after crying when they are under a lot of emotional stress. Emotional tears are may be associated with reddening of the eyes and/or face, sobbing (cough-like, convulsive breathing, and/or spasms of the whole upper body), increased heart rate, and decreased breathing rate. Emotional tears are produced in higher quantities than basal tears. They may be the same amount or more than reflex tears. Unlike, basal and reflex tears, emotional tears can be held back by the individual voluntarily, and they can stop when they want to.