Most broken blood vessels in the eye are subconjunctival hemorrhages, caused when a tiny blood vessel in the clear membrane covering the white of your eye ruptures and leaks blood into the space beneath it. The result looks alarming: a bright red patch that can spread across a large portion of the eye’s surface. Despite the dramatic appearance, the vast majority of these bleeds are harmless and triggered by mundane physical events like a hard sneeze, a coughing fit, or straining during a bowel movement. That said, recurrent or unusually persistent episodes sometimes point to something worth investigating further.
Why the Eye Bleeds So Easily
The conjunctiva, the thin transparent tissue draped over the white of your eye, is packed with small blood vessels. These vessels sit in layered networks, with a surface layer and a deeper layer that freely exchange capillary loops and form a dense mesh of blood flow near the edge of the cornea.1JAMA. Conjunctival Vessels That rich blood supply is useful: it helps nourish the eye’s surface and supports immune defense. But the trade-off is fragility. The vessels are extremely small and sit close to the surface with little structural cushioning. Even a modest spike in local blood pressure or a minor physical insult can pop one open. When it does, blood pools between the conjunctiva and the sclera (the tough white outer wall), and because the conjunctiva is translucent, you see the blood right through it.
The bleed itself is contained. Blood doesn’t enter the interior of the eye or touch your cornea, pupil, or retina. That’s why a subconjunctival hemorrhage almost never affects your vision. It looks terrible but acts like a bruise: the blood simply has to be reabsorbed over time.
Everyday Physical Triggers
The single most common category of cause is sudden physical strain, especially anything that briefly spikes pressure in your head, chest, or abdomen. Doctors sometimes call this the Valsalva maneuver: you bear down against a closed airway, pressure builds in the chest, and that pressure wave transmits to the veins and capillaries feeding the eye. When the pressure exceeds what a tiny vessel wall can handle, it bursts. During a Valsalva maneuver, a rapid increase in thoracic venous pressure can lead to rupture of superficial capillaries.2PubMed Central. A unique case of valsalva retinopathy in a conch blower
You don’t need to be doing anything extreme to trigger this. Common situations include:
- Coughing or sneezing: A violent sneeze or a prolonged coughing bout generates enough pressure to break a conjunctival vessel. People with bronchitis, whooping cough, or bad seasonal allergies often notice these bleeds.
- Vomiting: The abdominal force involved in retching is a textbook Valsalva trigger.
- Straining on the toilet: Constipation-related straining is one of the most frequently reported triggers.
- Heavy lifting or intense exercise: Weightlifting, in particular, involves repeated breath-holding under load. Competitive lifters sometimes develop subconjunctival hemorrhages after a max-effort set.
- Rubbing your eyes hard: Direct mechanical trauma to the conjunctival surface can rupture a vessel without any pressure buildup at all.
In many cases, people wake up with a red eye and have no memory of any triggering event. That’s normal. A minor strain during sleep, a cough you didn’t fully wake up for, or even sleeping face-down with pressure on the eye can be enough. The absence of a clear cause doesn’t make the bleed more worrisome on its own.
Systemic Health Conditions That Raise the Risk
While a one-off subconjunctival hemorrhage usually means nothing medically significant, the picture changes when bleeds keep happening. In patients with recurrent or persistent subconjunctival hemorrhage, further evaluation is warranted, including workup for systemic hypertension, bleeding disorders, systemic and ocular malignancies, and drug side effects.3PubMed Central. Subconjunctival hemorrhage: risk factors and potential indicators
High blood pressure is the most commonly identified systemic risk factor. Chronically elevated blood pressure weakens small vessel walls throughout the body, and the conjunctival capillaries are no exception. A person with uncontrolled hypertension may experience repeated subconjunctival hemorrhages without any obvious physical trigger because the baseline stress on their vessel walls is already high. In some cases, a broken blood vessel in the eye is what prompts a doctor to check blood pressure for the first time, and elevated readings are discovered.
Bleeding disorders, whether inherited conditions like hemophilia or von Willebrand disease or acquired problems like liver disease that impairs clotting factor production, can also predispose you to these bleeds. So can diabetes, which damages small blood vessels throughout the body over time. If you’re getting subconjunctival hemorrhages more than once or twice a year and there’s no obvious mechanical trigger, a basic blood workup checking your platelet count, clotting times, and blood pressure is a reasonable step.
Medications and Supplements That Thin the Blood
Anything that reduces your blood’s ability to clot makes a subconjunctival hemorrhage more likely and potentially more extensive. The usual suspects include prescription anticoagulants like warfarin and direct oral anticoagulants, antiplatelet drugs like aspirin and clopidogrel, and nonsteroidal anti-inflammatory drugs like ibuprofen when used regularly. These medications don’t cause the vessel to break, but once it does break, the bleed spreads further and takes longer to clear because the normal clotting response is blunted.
What surprises many people is that some over-the-counter supplements can have a similar effect. Fish oil, vitamin E in high doses, ginkgo biloba, and garlic supplements all have mild anticoagulant properties. Turmeric has drawn particular attention: one case report described a patient who experienced recurrent subretinal hemorrhages while taking a turmeric supplement, and once the supplement was stopped, the recurrent hemorrhages resolved and the retina remained attached.4PubMed Central. Recurrent Subretinal Hemorrhage in a Patient Taking a Turmeric Supplement: Case Report That’s a single case, and proving direct causation is difficult. But it’s a reasonable reminder: if you’re dealing with unexplained recurring eye bleeds, mention every supplement you take to your doctor, not just your prescription medications.
Alcohol is another common contributor. Heavy drinking affects platelet function and liver-dependent clotting factors, and a night of binge drinking can leave you more susceptible to broken vessels the next day, especially combined with vomiting or coughing.
Contact Lenses, Eye Surgery, and Direct Trauma
Mechanical injury to the eye’s surface is a straightforward cause that doesn’t require any systemic explanation. A poke to the eye, a foreign body hitting the conjunctiva, or aggressive rubbing can all rupture a vessel through direct physical disruption rather than pressure changes.
Contact lens wearers are at somewhat higher risk. Inserting and removing lenses involves repeated touching and minor manipulation of the eye’s surface, and dry or poorly fitted lenses can create low-grade friction that weakens conjunctival vessels over time. If you notice subconjunctival hemorrhages after switching to a new lens brand or wearing lenses for unusually long periods, the lenses are a plausible culprit.
Eye surgery, even routine procedures, can cause subconjunctival hemorrhage. Cataract surgery, LASIK, and injections around the eye all involve instruments near the conjunctiva. Subconjunctival hemorrhage can even occur as an associated finding in needle-related procedures during ocular anesthesia.5International Ophthalmology. Subconjunctival hemorrhage and vision loss after regional ocular anesthesia Post-surgical bleeding in the conjunctiva is generally expected and resolves without special treatment, though your surgeon will monitor for any deeper complications.
How Long It Takes to Heal
A typical subconjunctival hemorrhage follows a predictable timeline. In the first day or two, the blood patch is bright red. Over the next week, it gradually shifts to darker shades of red, then brownish-yellow, much like a skin bruise cycling through colors as hemoglobin breaks down. Complete resolution usually takes one to three weeks, depending on the size of the bleed. Larger hemorrhages that cover most of the white of the eye can linger closer to the three-week mark.
There’s no treatment that speeds this up meaningfully. Artificial tears can help with any mild irritation or scratchiness you feel from the elevated tissue, and cold compresses in the first day or two might limit further bleeding if the cause was mechanical. But mostly you wait. The blood is being reabsorbed by your body’s cleanup processes, and there’s no shortcut.
You should avoid rubbing the affected eye, and if you’re taking blood-thinning medications or supplements, talk to your doctor about whether a temporary adjustment makes sense. Don’t stop a prescription anticoagulant on your own: the risks of stopping that medication are usually far greater than the inconvenience of a red eye.
When a Red Eye Needs Medical Attention
A single painless subconjunctival hemorrhage with no vision changes almost never requires a doctor visit. But certain accompanying features should prompt you to get evaluated:
- Vision changes: Blurriness, double vision, or partial vision loss alongside the redness suggests the bleeding may involve deeper structures, not just the conjunctiva.
- Pain: Subconjunctival hemorrhages are generally painless. Significant eye pain could indicate increased eye pressure, a corneal abrasion, or internal bleeding.
- Trauma history: If the red eye followed a blow to the face, a fall, or any significant head injury, deeper damage needs to be ruled out.
- Recurrence: More than two or three episodes in a year, especially without obvious triggers, warrants a checkup for hypertension, bleeding disorders, or medication-related effects.3PubMed Central. Subconjunctival hemorrhage: risk factors and potential indicators
- Easy bruising elsewhere: If you’re also bruising easily on your arms or legs, or your gums bleed frequently, the eye bleed may be one piece of a broader clotting problem.
For anyone on anticoagulant therapy, a subconjunctival hemorrhage isn’t automatically an emergency, but it’s worth mentioning at your next appointment. If the bleeds become frequent while on these medications, your doctor may want to recheck your clotting levels or adjust your dose.
Broken Blood Vessels in Children
Subconjunctival hemorrhages happen in children too, and the causes overlap with adults: coughing fits, crying hard enough to strain, minor eye rubbing, or playground bumps. In newborns, the pressure of delivery itself can cause conjunctival bleeding, which resolves on its own in the first couple of weeks of life.
There is one context where eye hemorrhages in young children carry a very different significance. Retinal hemorrhages, which are bleeds inside the eye rather than on the surface, are a key finding in evaluating suspected abusive head trauma. The specific pattern of those hemorrhages holds diagnostic information that helps medical teams assess the likelihood of inflicted injury.6PubMed. The eye in child abuse: key points on retinal hemorrhages and abusive head trauma This doesn’t mean every red eye in a child raises concern for abuse. The distinction matters: a surface-level subconjunctival hemorrhage is visible to the naked eye and behaves like a bruise, while retinal hemorrhages are detected through a specialized eye exam and reflect forces transmitted to the back of the eye. Pediatricians are trained to distinguish between the two.
If your child has an uncomplicated red patch on the white of one eye with no vision problems, no pain, and a plausible trigger, the same reassurance applies as it does for adults. If there’s any accompanying injury, lethargy, vomiting, or other neurological concern, seek immediate evaluation.
Misconceptions That Cause Unnecessary Worry
The most common misconception about a broken blood vessel in the eye is that it signals a stroke or dangerously high blood pressure right now. While chronic hypertension is a risk factor for recurrent subconjunctival hemorrhages, a single episode does not mean your blood pressure is spiking to crisis levels. Plenty of people with perfectly normal blood pressure get these bleeds after sneezing or rubbing their eyes.
Another frequent worry is that the blood will spread to the inside of the eye or damage vision. It won’t. The conjunctiva is a separate layer from the structures responsible for vision, and blood trapped beneath it stays contained. Your cornea, lens, and retina are unaffected by a surface-level bleed.
Some people also assume the bleed is contagious, probably because it looks similar to the redness caused by conjunctivitis (pink eye). Subconjunctival hemorrhage is not an infection, doesn’t produce discharge, and can’t be spread to another person. The two conditions look different on close inspection: conjunctivitis produces diffuse pinkness with discharge and irritation, while a subconjunctival hemorrhage creates a solid, well-defined patch of deep red blood.
Aging and the Fragility Factor
Subconjunctival hemorrhages become more common as you get older, and that makes biological sense. Aging weakens blood vessel walls throughout the body, including the tiny capillaries in the conjunctiva. Older skin bruises more easily for the same reason, and the eye’s surface vessels are no different. The conjunctiva itself thins with age, providing even less cushioning around those vessels.
Adding to this, older adults are more likely to be taking medications that affect clotting. Aspirin for cardiovascular prevention, anticoagulants for atrial fibrillation, and anti-inflammatory drugs for arthritis are all common in people over 60 and all contribute to easier bleeding. If you’re in this age group and notice occasional subconjunctival hemorrhages, the combination of aging vessels and blood-thinning medication is the most probable explanation. It’s still worth mentioning to your doctor, particularly if the episodes are new or increasing in frequency, but it rarely signals anything beyond what’s already being managed.
Dry eye syndrome, which is also more prevalent with age, adds another layer. Chronic dryness leads to more eye rubbing, and rubbing is one of the simplest mechanical triggers for these bleeds. Treating the underlying dryness with artificial tears or other interventions can indirectly reduce how often you break a conjunctival vessel.