A broken blood vessel in your eye is almost always a subconjunctival hemorrhage, a bright red patch on the white of the eye caused when a tiny blood vessel just beneath the surface ruptures and leaks blood. It looks alarming but is usually painless and harmless. The most common triggers are everyday physical actions that briefly spike pressure in the small veins of your head and face: coughing, sneezing, straining, vomiting, or even rubbing your eye too hard.
In many cases, you won’t be able to pinpoint the exact moment it happened. The blood vessel may have ruptured during sleep or during a sneeze you barely noticed. Understanding the full range of causes can help you figure out whether yours is a one-time event or something worth investigating.
Physical Strain and Pressure Spikes
The blood vessels on the surface of your eye are extremely small and fragile. Any action that temporarily raises venous pressure in your head can cause one to burst. The classic triggers include:
- Coughing or sneezing, especially forceful or prolonged bouts
- Vomiting
- Straining on the toilet (constipation is an underappreciated cause)
- Heavy lifting, pushing, or bending forward
- Rubbing your eye too vigorously
These are all variations of what’s called a Valsalva maneuver, where you bear down or strain against a closed airway. That effort momentarily backs up blood flow in the veins of your head and neck, and the weakest vessel gives way. Even a single strong sneeze is enough to pop a capillary on the surface of the eye.
Contact Lenses and Minor Trauma
Subconjunctival hemorrhages are very common among contact lens wearers. The routine pressure of putting lenses in and taking them out places repeated mechanical stress on the eye’s surface, making vessel rupture more likely over time. You don’t need a dramatic injury. A light bump, an accidental poke from a finger or a child’s elbow, or even vigorous face washing can be enough to trigger one.
Eye infections can also play a role. Inflammation makes blood vessels more fragile and prone to leaking, so a hemorrhage that appears during a bout of conjunctivitis or another surface infection isn’t unusual.
Medications That Increase Bleeding Risk
Blood-thinning medications don’t directly cause the vessel to break, but they make it much harder for the break to seal quickly, so the resulting bleed spreads further and looks worse. Prescription anticoagulants (like warfarin) and antiplatelet drugs (like aspirin) are the most common culprits. Over-the-counter pain relievers that thin the blood, such as ibuprofen, can also contribute.
If you take any blood thinner and notice recurrent eye hemorrhages, that’s worth mentioning to your doctor. In rare cases, repeated hemorrhages in someone on anticoagulant therapy signal that their dosing needs adjustment.
Underlying Health Conditions
A single broken blood vessel in your eye rarely signals a deeper health problem. But when hemorrhages recur, there’s usually an underlying cause. High blood pressure is the most commonly linked condition because chronically elevated pressure weakens vessel walls throughout the body, including in the eye. Diabetes damages small blood vessels over time and raises the risk as well.
Less common but more serious possibilities include bleeding disorders, where the blood doesn’t clot properly, and certain blood cancers like leukemia that affect clotting factors. These conditions almost always come with other symptoms, not just eye bleeding, but recurrent subconjunctival hemorrhages can occasionally be the first visible sign. That’s why doctors sometimes order blood clotting tests or a complete blood count if you keep getting them without an obvious physical trigger.
Broken Blood Vessels in Newborns
If you’ve noticed a red spot on a newborn’s eye, it’s surprisingly common. About 9% of full-term infants are born with a subconjunctival hemorrhage, and the rate is higher in babies with higher birth weights. The cause is compression of the chest during passage through the birth canal, which creates a sudden spike in venous pressure in the head and neck. It’s the same pressure mechanism that causes hemorrhages in adults who strain or cough. In newborns, these resolve on their own without treatment.
How It Heals
A subconjunctival hemorrhage follows a predictable color progression as your body reabsorbs the trapped blood. It typically starts bright red, then shifts to orange, yellow, and finally clears completely. Most hemorrhages resolve within two to three weeks without any treatment. The blood has nowhere to drain externally, so it gradually breaks down in place, much like a bruise on your skin.
You can use artificial tears if the eye feels mildly irritated or scratchy, but the hemorrhage itself doesn’t need medication. Avoid rubbing the eye, which could worsen the bleed or trigger a new one.
When Red in the Eye Is More Serious
A subconjunctival hemorrhage sits on the white part of your eye, is painless, and doesn’t affect your vision. If what you’re experiencing doesn’t match that description, the cause may be something different.
A hyphema is bleeding inside the eye, between the cornea (the clear front surface) and the iris (the colored part). Instead of a red patch on the white of your eye, a hyphema looks like blood pooling in front of your iris. The key differences: a hyphema hurts, it blurs or distorts your vision, and it requires emergency medical care. In children, a hyphema can cause unusual sleepiness, which may also indicate a head injury. Nausea and vomiting alongside eye bleeding can mean the pressure inside the eye has risen to dangerous levels.
Any bleeding in the eye accompanied by pain, vision changes, or new blood that seems to be accumulating rather than fading needs prompt evaluation. A simple subconjunctival hemorrhage never causes these symptoms. If yours does, that’s a different condition entirely.
When Recurrence Matters
One or two broken blood vessels a year with an obvious trigger, like allergy season sneezing or a heavy gym session, is generally nothing to worry about. The threshold for concern is when hemorrhages keep coming back without a clear cause, or when they’re unusually large or slow to resolve. At that point, the hemorrhage itself isn’t the problem. It’s a signal pointing toward something systemic: uncontrolled blood pressure, a clotting disorder, a medication side effect, or in rare cases, a blood cancer.
A thorough workup for recurrent hemorrhages typically includes blood pressure measurement, a complete blood count, and clotting studies. These tests are simple and can either provide reassurance or catch a condition that needs treatment before it causes more serious complications elsewhere in the body.