When emotions overwhelm, tears often follow, leading to noticeable redness in the eyes. This temporary phenomenon involves physiological responses. The transformation of clear eyes to a flushed appearance after crying results from processes within the tear system and surrounding blood vessels.
The Mechanics of Tear Production
Tears originate from the lacrimal glands, located above the outer corner of each eye. These glands continuously produce fluid that spreads across the eye’s surface with each blink, lubricating and clearing debris. The tear film provides hydration and contains components that protect against bacteria.
After lubricating the eye, tears drain through small openings called puncta in the inner corners of the eyelids. From there, tears travel through small canals into the lacrimal sac and down the nasolacrimal duct, emptying into the nasal cavity. This drainage system explains why crying can lead to a runny nose. When tear production increases significantly during crying, this system can become overwhelmed, causing tears to spill over the eyelids.
How Blood Vessels React to Crying
The redness observed in the eyes after crying is primarily due to the dilation of blood vessels in the conjunctiva. The conjunctiva is a clear membrane that covers the white part of the eye and the inside of the eyelids. Normally, these vessels are not prominently visible, contributing to the eye’s white appearance. When they dilate, more blood flows through them, making them distinctly visible and giving the eye a red or “bloodshot” look.
This vascular reaction is influenced by the body’s autonomic nervous system. The parasympathetic branch of this system stimulates the lacrimal glands to produce tears, particularly during emotional responses. To support increased tear production, blood vessels supplying the lacrimal glands and eye surface also dilate to deliver necessary fluid components. The irritation from excessive tears overflowing onto the eye’s surface can also trigger a localized inflammatory response, further contributing to blood vessel dilation.
The Impact of Different Tear Types
Tears vary in chemical composition depending on their purpose. Basal tears constantly lubricate the eye, while reflex tears flush out irritants. Emotional tears, produced in response to strong feelings, have a distinct chemical makeup. These tears contain higher concentrations of stress hormones and other compounds.
While blood vessel dilation is the primary cause of redness, unique components in emotional tears can play an exacerbating role. These higher levels of hormones and proteins can act as mild irritants on the eye’s surface. This irritation can enhance the local inflammatory response, further contributing to vascular changes and increased redness. These specific compounds in emotional tears differentiate their effect from basal or reflex tears.
Why Redness Lingers
The duration of eye redness after crying varies depending on the intensity and length of the crying episode. When crying is prolonged or vigorous, blood vessels remain dilated longer. The body’s natural recovery process involves these dilated vessels gradually constricting to their normal size, reducing the red appearance.
Rubbing the eyes during or after crying can also prolong and worsen redness. The conjunctiva can become irritated or damaged by friction, leading to additional inflammation and more pronounced blood vessel dilation. Introducing germs from hands through rubbing can also lead to infection, causing further redness. The lingering redness is a temporary physiological response as the eyes return to their normal, non-irritated state.