A broken blood vessel in the eye, medically known as a subconjunctival hemorrhage, occurs when a tiny vessel ruptures beneath the delicate, transparent membrane covering the white part of the eye. This membrane, called the conjunctiva, contains numerous small, fragile blood vessels that can easily break. While the sight of a red eye can be startling, this condition is generally considered harmless and is a frequent cause of sudden ocular redness. It is essentially the eye’s version of a bruise.
The Appearance of a Subconjunctival Hemorrhage
The most defining visual trait of a subconjunctival hemorrhage is a patch of bright, uniform red blood across the white part of the eye, known as the sclera. Because the blood is contained beneath the clear conjunctiva, the patch appears sharply defined and intensely colored. The hemorrhage may be a small spot or cover an entire quadrant of the eye, making the entire white area appear red and bloody.
This blood does not seep into the pupil or the iris, meaning the condition does not typically cause any changes to vision. Unlike conditions like pink eye, a subconjunctival hemorrhage does not cause discharge or tearing. The condition is usually painless, though some individuals may report a minor scratchy or gritty feeling on the surface of the eye.
Common Triggers and Mechanisms
The vessels in the conjunctiva are particularly fragile and can break due to sudden increases in pressure within the head or chest. This mechanism, often referred to as a Valsalva maneuver, involves momentarily holding one’s breath and straining, which causes a spike in venous pressure that can rupture a small vessel. A simple, strong physical action like a violent sneeze or a forceful coughing fit is one of the most common causes of this pressure increase.
Other common actions include vomiting, intense straining during a bowel movement, or heavy lifting. Even minor trauma, such as aggressively rubbing the eye, can be enough to cause a vessel to burst. Systemic factors can also increase the likelihood of a hemorrhage, as certain blood-thinning medications or underlying conditions like high blood pressure can compromise vascular integrity and promote bleeding.
When to Consult a Doctor
A simple subconjunctival hemorrhage requires no specialized treatment because the body naturally reabsorbs the blood. The process of healing typically takes between one and three weeks, with larger patches requiring more time to resolve. As the blood is reabsorbed, the bright red patch may change color, fading to a more yellow or pinkish hue before disappearing completely.
While the condition is usually harmless, there are specific symptoms that signal a need for immediate medical attention:
- If the eye pain is more than a minor irritation.
- If you experience blurry or altered vision.
- If the hemorrhage was associated with a head or eye injury.
- If the redness does not begin to clear within two to three weeks.
- If the red patches occur frequently.
A medical evaluation is warranted in these cases to rule out a more serious underlying condition.