Tears are an essential part of your eye’s health. Your eyes will not function properly, and you can experience significant discomfort if you don’t have a proper supply of tears. You may have complained to your eye doctor that your eyes are running, but they say you have dry eyes. How you have dry eyes if you have an excess of tears?
Not all tears are created equal. While commonly linked to feelings of sadness or joy, tears are much more than mere indicators of emotional states. They play a crucial role in eye health and vision. Tears can be categorized into three distinct types: basal, reflex, and emotional. Each type has unique compositions and functions, highlighting the complex nature of this seemingly simple feature of the human body.
1. Basal Tears: The Essential Eye Protectors
Basal tears are the unsung heroes of our daily lives. They are continuously secreted to keep the eyes lubricated without you even thinking about it. These tears form a thin, protective layer over the cornea, which is essential for nourishing our eyes and keeping them moist and safeguarded from dust and other irritants.
Basal tears consist of three layers: an oily layer, a watery layer, and a mucous layer. The oily layer, produced by the meibomian glands, prevents evaporation of the tear film. The watery layer, produced by the lacrimal glands, hydrates and nourishes the cornea. And the mucous layer helps the tears adhere to the eye’s surface.
Our eyes become dry and uncomfortable without basal tears, leading to dry eye syndrome. A scratchy or sandy feeling is typical when deficient in basal tears. They also serve an essential function in maintaining a clear vision. Your vision can blur as your car windshield blurs with old wiper blades. Each blink spreads basal tears across the eye’s surface, providing a smooth optical surface critical for sharp vision.
2. Reflex Tears: Nature’s Response to Irritants
Reflex tears are produced in response to irritants in the eyes. These include substances like onion vapors, smoke, or even a strong gust of wind. Their primary function is to flush out these irritants and protect the eye from harm. Reflex tears are released in larger quantities than basal tears and contain significantly more antibodies to help fight bacteria and other pathogens that might enter the eye. But they contain less nourishment than basal tears, leading to a diagnosis of dry eye when you have an excess of tears.
This type of tear is produced by the same lacrimal glands that produce basal tears but are triggered by a different mechanism. When an irritant is detected, a reflex arc involving the nerves of the eyes and the brain is activated, producing these types of tears.
3. Emotional Tears: The Tears of Feelings
Emotional tears are perhaps the most intriguing and unique of the three types. Triggered by various emotions, from deep sadness and grief to extreme joy and relief, these tears contain a chemical makeup different from basal or reflex tears. Studies have found that emotional tears contain higher levels of stress hormones, such as adrenocorticotropic hormone (ACTH), and neurotransmitters like leucine enkephalin, an endorphin that reduces pain.
The purpose of emotional tears is still a subject of research and debate. Some theories suggest that they help to soothe and regulate intense emotions, possibly by releasing these hormones. Others believe that crying has evolved as a social signal, conveying vulnerability and fostering human empathy and social bonds.
Conclusion
Tears and the pathology of tears are much more complicated than expected. The study of tears, from their chemical composition to their psychological and social implications, is a fascinating field that bridges biology, psychology, and sociology. The three types of tears – basal, reflex, and emotional – each serve distinct and vital functions. They protect our eyes, clear them of irritants, and help us to express and process our deepest emotions. Any breakdown of the production, distribution, or function of tears can cause discomfort, blurred vision, and, in severe cases, damage to the eye.