A burst blood vessel in the eye is almost always a subconjunctival hemorrhage, a harmless leak of blood from a tiny capillary just beneath the clear membrane covering the white of your eye. It looks alarming (a bright red patch that can spread across the white of your eye) but causes no pain and no vision loss. Most cases heal on their own within two weeks.
Why Eye Blood Vessels Burst
The conjunctiva, the thin transparent tissue that covers the white of your eye, is packed with fragile capillaries. When one of these tiny vessels breaks, blood gets trapped beneath the membrane with nowhere to go. Because the conjunctiva is see-through, even a small amount of blood creates a vivid red blotch that looks much worse than it is.
Sometimes the cause is obvious. Other times you wake up, look in the mirror, and find a red patch with no idea how it got there. Both scenarios are common, and in many cases no specific trigger is ever identified.
Physical Triggers That Raise Pressure
The most common identifiable cause is a sudden spike in pressure inside your chest or abdomen, which pushes venous pressure upward toward the head and eyes. This is the same mechanism behind the “bearing down” feeling you get during certain activities. That pressure surge can be enough to pop a delicate capillary in the eye.
Specific triggers include:
- Sneezing or coughing, especially prolonged bouts from allergies or a cold
- Vomiting
- Straining during a bowel movement
- Heavy lifting or strenuous exercise
- Labor and childbirth
- Sexual intercourse
- Blowing into a musical instrument
All of these involve forceful exertion against a closed airway (or something close to it), which temporarily backs up blood flow and raises pressure in the small vessels near the surface of the eye.
Eye Rubbing and Minor Trauma
Rubbing your eyes vigorously, getting bumped during sports, or even sleeping face-down on your hand can be enough to rupture a conjunctival capillary. Contact lens wear can also irritate the surface of the eye and contribute. If you notice a burst vessel after a night of poor sleep or allergy-driven eye rubbing, that friction is the likely culprit.
Medical Conditions That Weaken Blood Vessels
High blood pressure and diabetes are the two main chronic conditions that raise your risk. Both damage blood vessel walls over time, making capillaries more fragile and more prone to breaking under ordinary pressure. If you experience recurrent subconjunctival hemorrhages, a blood pressure check is a standard first step. Repeated episodes can be an early signal that blood pressure or blood sugar isn’t well controlled.
Medications and Supplements
Blood-thinning medications make it easier for bleeding to start and harder for it to stop, so they increase the chance of a burst vessel in the eye. This includes prescription anticoagulants like warfarin, newer oral blood thinners, and antiplatelet drugs. Even over-the-counter options like aspirin and NSAIDs (ibuprofen, naproxen) can raise the risk, particularly if you take them regularly or combine them with other blood thinners. Fish oil and other supplements with mild anticoagulant effects may also contribute.
If you’re on blood thinners and notice these hemorrhages happening more than once, it’s worth mentioning to the prescribing provider. The medication itself usually doesn’t need to change, but recurring bleeding may prompt a closer look at dosing or drug interactions.
What Healing Looks Like
Most burst blood vessels heal completely within two weeks without any treatment. The progression looks a lot like a bruise elsewhere on your body. The bright red patch gradually shifts to darker shades, sometimes taking on a purple or greenish hue, and eventually fades to a yellowish tint before the white of your eye returns to normal. No medication speeds up this process. Your body simply reabsorbs the trapped blood at its own pace.
If the area feels scratchy or mildly irritated, over-the-counter artificial tears can help with comfort. Avoid rubbing the eye, which could slow healing or cause additional vessel damage.
When a Red Eye Is Something More Serious
A standard subconjunctival hemorrhage is painless and doesn’t affect your vision. If you have pain, changes in how well you can see, sensitivity to light, or bleeding that appears to pool inside the colored part of your eye rather than on the white surface, the situation may be different.
Bleeding inside the front chamber of the eye (between the cornea and the iris) is called a hyphema. Unlike a simple burst vessel on the surface, a hyphema hurts, can blur your vision, and typically results from direct trauma like a blow to the eye. A hyphema and a subconjunctival hemorrhage can happen at the same time after an injury, but they require very different levels of attention. A hyphema needs prompt evaluation.
A red eye accompanied by discharge, a gritty feeling, or light sensitivity is more likely conjunctivitis (pink eye) or another inflammatory condition, not a burst vessel. The visual signature is different too: conjunctivitis causes generalized redness and dilated surface vessels, while a burst vessel creates a distinct, solid red patch.
Reducing Your Risk
You can’t prevent every burst vessel, but a few practical steps lower the odds. Treating allergies or coughs promptly reduces the strain of repeated sneezing and coughing. Eating enough fiber and staying hydrated cuts down on straining during bowel movements. If you lift weights, exhaling through effort rather than holding your breath limits the pressure spike. And if you tend to rub your eyes, keeping lubricating drops on hand can relieve the itch before you reach for your eyes.
For people with high blood pressure or diabetes, keeping those conditions well managed is the most effective long-term strategy. Stable blood pressure means healthier, more resilient vessel walls throughout the body, including in the eye.