When you rub your eyes, you often trigger a natural response that causes tears to flow. This isn't necessarily an emotional reaction, but rather a physical one designed to protect and maintain the health of your eyes.
The Science Behind Tears and Rubbing
The primary reason rubbing your eyes causes tears is simple: stimulation. Your eyes have sensitive surface tissues and built-in mechanisms to keep them clean and moist.
According to information from July 25, 2017, "Rubbing stimulates tears to flow," and this action serves two key purposes:
- Lubricating Dry Eyes: Just like other parts of your body, your eyes need moisture to function correctly. Rubbing can signal to the tear glands (specifically the lacrimal glands) that the eye surface might be dry or needs lubrication. This triggers the release of basal tears, which are the type of tears constantly produced in small amounts to keep eyes moist.
- Removing Dust and Other Irritants: Our eyes are exposed to the environment, and tiny particles like dust, pollen, or even loose eyelashes can land on the surface. Rubbing can make you aware of these irritants. The physical stimulation prompts the tear glands to release reflex tears. These tears are produced in larger quantities than basal tears and are specifically designed to flush out foreign objects, protecting the cornea.
Think of it as a built-in cleaning and maintenance system that rubbing activates.
How Stimulation Works
Rubbing the eyelids or the eye itself (through the eyelids) puts pressure on the eye and can also stimulate nerve endings on the surface of the eye (the cornea and conjunctiva). This stimulation sends signals to the brain, which in turn instructs the lacrimal glands to produce more tears.
Factors That Might Increase Tearing
While rubbing always can stimulate tears, certain conditions might make you more likely to tear up when you do it:
- Dry Eye Syndrome: If your eyes are already dry, rubbing might be a subconscious attempt to stimulate moisture, leading to tear production.
- Allergies: Allergic reactions can make eyes itchy, leading to rubbing. Allergies also often cause increased tear production as the body tries to flush out allergens.
- Presence of Irritants: If there's actually something in your eye (dust, grit), rubbing will not only stimulate tears but also highlight the need for those tears to wash the irritant away.
- Fatigue: Tired eyes can often feel dry or irritated, prompting rubbing and subsequent tearing.
Is Rubbing Your Eyes Harmful?
While it's a natural reflex, frequent or vigorous eye rubbing is generally not recommended.
- It can potentially scratch the cornea.
- It can worsen existing eye conditions like keratoconus (a thinning of the cornea).
- It can break delicate blood vessels, leading to redness or bruising.
- It can transfer germs from your hands to your eyes, increasing the risk of infection.
Instead of rubbing, try these alternatives if your eyes feel irritated or dry:
- Use artificial tears (eye drops) for lubrication.
- Rinse your eyes gently with clean water or saline solution if you suspect an irritant.
- Use a warm compress if irritation is due to blocked oil glands.
- Consult an eye care professional if irritation, dryness, or excessive tearing persists.
In summary, rubbing your eyes often leads to crying because the physical stimulation activates the body's natural tear production mechanism, which serves to lubricate the eyes and remove any potential irritants.
