A broken blood vessel in your eye is almost always a subconjunctival hemorrhage, a harmless condition where a tiny blood vessel ruptures and leaks blood beneath the clear surface layer of your eye. It looks alarming, but it typically resolves on its own within two weeks. The causes range from everyday physical strain to underlying health conditions, and in many cases, you may never pinpoint exactly what triggered it.
How It Happens
The white of your eye (the sclera) is covered by a thin, transparent membrane called the conjunctiva. This membrane contains many tiny blood vessels. When one of these vessels breaks, blood leaks into the space between the conjunctiva and the sclera, spreading out beneath the surface. Because the blood has nowhere to drain, it pools into a bright red patch that can look startling, even though the amount of blood is extremely small.
Think of it like a bruise under the skin, just more visible because the tissue covering it is transparent.
Physical Strain and Pressure Spikes
The most common trigger is a sudden increase in pressure through the veins in your upper body. When you strain against a closed airway, pressure builds in your chest and abdomen, which backs up into the venous system and raises pressure inside the small blood vessels of your eye. This can rupture fragile capillaries on the eye’s surface.
Everyday activities that create this kind of pressure spike include:
- Coughing or sneezing, especially prolonged bouts during a cold or allergies
- Vomiting
- Heavy lifting or intense physical exertion
- Straining during a bowel movement
- Labor and childbirth
- Blowing into musical instruments
A single hard sneeze is enough. You don’t need to be doing anything extreme. Many people wake up with a broken blood vessel and never identify the cause, possibly because it happened during sleep from an unconscious cough or an awkward position that temporarily raised pressure.
Eye Rubbing and Contact Lenses
Mechanical friction is another straightforward cause. Rubbing your eyes vigorously, especially when they’re dry or itchy, can physically damage the delicate capillaries on the eye’s surface. Contact lens wearers face a higher risk of this kind of minor trauma because the lens itself creates friction during insertion, removal, or if the lens shifts during wear. In younger adults, contact lens use is actually the leading cause of broken blood vessels in the eye.
High Blood Pressure and Other Health Conditions
If broken blood vessels in your eye keep happening, an underlying condition may be weakening your blood vessels. High blood pressure is the most significant medical cause, particularly in older adults. Chronically elevated blood pressure damages the walls of small blood vessels throughout your body, including those in your eyes, making them more prone to spontaneous rupture.
Other conditions linked to recurrent episodes include diabetes, high cholesterol, and atherosclerosis (hardening of the arteries). All of these affect blood vessel integrity over time. The connective tissue beneath the conjunctiva also naturally becomes more fragile with age, which explains why broken blood vessels in the eye become more common as people get older. A single episode is rarely a sign of anything serious, but repeated episodes, especially without an obvious physical trigger, are worth mentioning to your doctor, as they can be an early signal of uncontrolled blood pressure.
Blood Thinners and Medications
Medications that reduce your blood’s ability to clot can make you more susceptible. If you take anticoagulants (blood thinners) or even over-the-counter pain relievers like aspirin or ibuprofen regularly, minor vessel damage that would normally seal itself quickly may instead produce a visible hemorrhage. That said, spontaneous eye bleeding in people on anticoagulant therapy is still considered rare. The medication doesn’t cause the vessel to break; it just makes it harder for the break to stop bleeding quickly, so a smaller injury becomes more noticeable.
What Recovery Looks Like
Most broken blood vessels heal within two weeks without any treatment. Larger patches of blood may take a bit longer. As the blood is gradually reabsorbed, the bright red color shifts through stages similar to a fading bruise. You may notice the area turn orange, then yellow, before clearing completely. A slight yellowish tint to the white of your eye near the end of healing is normal.
The spot itself shouldn’t cause pain, and your vision should be completely unaffected. Some people notice a mild scratchy sensation, but nothing beyond that. Cold compresses and artificial tears can help if the area feels slightly irritated.
How to Tell It’s Not Something Serious
A subconjunctival hemorrhage is easy to distinguish from more concerning eye conditions. The key differences come down to location, pain, and vision.
A harmless broken blood vessel sits on the white of the eye, causes no pain, and doesn’t affect your sight at all. A hyphema, which is a more serious condition, involves bleeding inside the front chamber of the eye, between the cornea and the iris. With a hyphema, you may see blood pooling over the colored part of your eye or blocking your pupil. Hyphemas are painful, cause light sensitivity, and blur or block vision. They typically result from a direct blow to the eye and need prompt medical attention.
If your broken blood vessel comes with eye pain, vision changes, bleeding that covers the iris or pupil, or if it keeps recurring without explanation, those are signs that something beyond a simple surface vessel rupture may be going on.