You may shed tears out of grief for a loved one, feel emotional while watching a great movie, or simply while cooking. Whether it’s rare or a frequent occurrence, this is a human experience.
Professor of Ophthalmology Daniela Oehring from the University of Plymouth, UK, states that there are three types of tears, each with different compositions.
There are three types of tears, one of which is called emotional tears, but regardless of what this boy is going through, we all hope he will be okay. (Photo: Yuji Arikawa via Getty Images).
Most people often think of emotional tears, which are shed when a person feels sad, distressed, or overly joyful, such as when reuniting with a long-lost loved one.
In addition, there are two other types of tears: basal tears, which help to moisturize, lubricate the eyes, provide nutrients to the eye tissue, and remove small debris; and reflex tears, which are produced when the body reacts to irritants such as smoke or onion vapors.
Basal tears contain a high concentration of salt ions and other electrolytes, along with antibacterial proteins, while reflex tears and emotional tears have a higher water content and lower fat and protein levels compared to basal tears. Compared to reflex tears, emotional tears have a higher concentration of hormones that are released when the body is under stress.
All types of tears mentioned above adhere to a thin film that covers and nourishes the cornea, the transparent tissue at the front of the eye. This tear film has three layers.
- The outer layer consists of oils secreted by the meibomian glands in the eyelids, which help prevent the eyes from drying out.
- The second layer is primarily produced by the lacrimal glands, serving to lubricate the eyes and provide proteins, oxygen, and electrolytes.
- The innermost layer, closest to the cornea, contains a type of mucus-like protein called mucin, which helps the tear film adhere to the surface of the eye.
On average, a person produces about 1 to 4 microliters of tears per minute, equating to approximately 5.76 ml per day. These are primarily basal tears, produced continuously rather than the full drops created by emotional or reflex responses to stimuli.
However, the amount of basal tears varies from person to person depending on the environment and activities they are engaged in. For instance, if you are cycling, the rate of moisture evaporation is higher than when walking, and the body produces more tears, or if you are in a steam room, tear production will be lower.
Typically, tears evaporate partially, with the remainder draining through the tear ducts, but because emotional and reflex tears are produced in large quantities in a short time, they can overflow from the eyes.
If the body produces too few tears, your eyes can become dry, not sufficiently moisturized and lubricated, leading to various eye conditions. Numerous factors contribute to a decrease in the body’s natural tear production, including smoking, poor nutrition, excessive screen time, and insufficient blinking.
Age also affects the ability to produce natural tears, and certain diseases can lead to dry eyes, such as Sjögren’s syndrome, where immune cells negatively impact the lacrimal glands and reduce their ability to keep the eyes moist. Individuals with this syndrome may even be unable to produce reflex tears.
