A sudden, bright red patch on the white of your eye can look alarming. In most cases it’s a subconjunctival haemorrhage — a tiny blood vessel has burst under the clear surface layer (the conjunctiva), leaving a flat red stain on the sclera. It’s usually painless, doesn’t affect vision and behaves like a skin bruise, clearing on its own within 1–3 weeks. You might notice mild grittiness or irritation, but no discharge.
This guide explains the cause of a blood vessel bursting in the eye, the everyday triggers you might not expect, and the medical conditions and medicines that raise your risk. You’ll learn what’s normal, when to seek care, how it’s diagnosed, simple home relief, recovery and recurrence, plus prevention tips. We also outline look‑alike conditions to rule out, advice for contact lens wearers and those on blood thinners, and where to get help in Randwick and the Eastern Suburbs.
What causes a blood vessel in the eye to burst (subconjunctival haemorrhage)?
A subconjunctival haemorrhage happens when a tiny surface capillary in the conjunctiva breaks and leaks a small amount of blood over the white of the eye. This often follows a brief pressure spike inside your head and neck or minor trauma to the eye. It can also occur without a clear cause, and because the bleed sits on the surface (not inside the eye), vision stays normal.
- Straining moments: coughing, sneezing, vomiting or straining on the toilet.
- Rubbing or irritation: vigorous eye rubbing, dry or gritty eyes.
- Minor knocks: bumps to the eye or face; sometimes after eye surgery.
- Effort and posture: heavy lifting or bending forward.
- Contact lenses: insertion, removal or friction from a dry lens.
Common triggers you might not expect
Small, sudden pressure spikes or simple friction can split a tiny surface vessel, even when your eye otherwise feels normal. These everyday moments are often‑overlooked causes of a blood vessel bursting in the eye.
- Forceful coughing or sneezing.
- Vomiting or straining on the toilet.
- Heavy lifting, pushing, or bending forward.
- Vigorous eye rubbing or dry, gritty eyes.
- Contact lens insertion/removal or a dry lens.
- Intense pushing during childbirth.
Medical conditions and medicines that raise your risk
Often there’s no single cause of a blood vessel bursting in the eye, but certain health conditions and medicines make the tiny surface capillaries more likely to split with everyday strain. These factors don’t cause the bleed by themselves; they lower the threshold so a cough, rub or minor knock triggers a subconjunctival haemorrhage.
- High blood pressure (hypertension): raises stress on fragile surface vessels.
- Diabetes: can affect small blood vessels, making them easier to rupture.
- Blood‑clotting disorders: such as haemophilia or von Willebrand disease.
- Blood thinners: warfarin, aspirin and other anticoagulants/antiplatelets increase bleeding.
- Eye surface inflammation or dryness: conjunctivitis or dry eye adds friction.
- Contact lens wear or recent eye surgery: increases irritation and susceptibility.
Who is most at risk?
Anyone can develop a subconjunctival haemorrhage, but it’s more common with age, especially in people 65+ and those with vascular conditions such as high blood pressure or diabetes. Risk also rises if you wear contact lenses, have dry or inflamed eyes, recently had eye surgery, take blood thinners like warfarin or aspirin, or have a bleeding/clotting disorder. Frequent bouts of coughing, sneezing, vomiting or straining (including constipation or heavy lifting) can tip a fragile surface vessel into bleeding.
What it looks and feels like (and what isn’t normal)
A subconjunctival haemorrhage looks like a flat, bright red patch on the white of the eye. Vision stays normal, there’s no discharge and usually no pain — at most a mild gritty or itchy sensation. The blood sits on the surface and doesn’t move with blinking. As it heals, the colour often changes from red to brown to yellow, like a fading bruise. Even when the cause of a blood vessel bursting in the eye is minor, the appearance can be dramatic.
- Eye pain or a severe ache.
- Any change in vision (blurring, shadows or loss).
- Discharge or marked swelling of the eye or eyelids.
- Blood inside the front of the eye (not just on the white).
- Frequent recurrences or a red eye after an injury.
Is it serious? When to seek medical care
Most subconjunctival haemorrhages are harmless and settle without treatment in 1–3 weeks. The cause of a blood vessel bursting in the eye is often a minor strain or rub, not a sign of damage inside the eye. That said, a red eye with any “not normal” features deserves prompt assessment.
- Eye pain or a feeling of pressure.
- Any change in vision (blur, shadow, loss).
- After an eye injury or if blood seems inside the eye (possible hyphema).
- Recurrent episodes or easy bruising/bleeding elsewhere.
- On blood thinners (warfarin/aspirin) and it’s large or keeps happening.
- Marked swelling or discharge.
- Not clearing within 2–3 weeks.
How it’s diagnosed in clinic
Most cases are diagnosed at a glance. Your clinician confirms a flat red patch on the white of the eye beneath a clear surface, with normal vision and no discharge. Because the cause of a blood vessel bursting in the eye is usually minor, tests are often unnecessary unless red flags are present.
- History: triggers, recent injury, contact lens wear, and medicines (especially blood thinners).
- Eye exam: visual acuity, pupils, slit‑lamp to confirm a superficial bleed; fluorescein if abrasion suspected.
- Vitals: blood pressure check; consider diabetes screening.
- Further tests when needed: recurrent/large bleeds or trauma may prompt clotting studies and assessment for hyphema or other injury.
What you can do at home: treatment and relief
Most subconjunctival haemorrhages don’t need treatment. There’s no way to speed up reabsorption of the blood; focus on comfort and reducing irritation while it heals. Even when the cause of a blood vessel bursting in the eye is a simple cough or rub, a few sensible steps help it settle smoothly.
- Use artificial tears: Lubricating drops ease itchiness or grittiness.
- Avoid rubbing: Hands off the eye; rubbing can worsen or re‑bleed the area.
- Pause contact lenses: Leave lenses out until the white of the eye looks normal again.
- Ease straining: Go gentle on heavy lifting; avoid straining on the toilet and manage coughs.
- Stick with prescribed meds: Don’t stop blood thinners unless your doctor advises; seek advice if bleeds are large or frequent.
- Be patient: Colour will fade like a bruise over 1–3 weeks; no special drops speed healing.
Recovery timeline and recurrence
Most subconjunctival haemorrhages look alarming at first, then fade like a bruise. Expect the colour to shift from bright red to brown/yellow. Most clear in 1–2 weeks; larger patches may take up to 2–3 weeks. No treatment speeds this up.
Recurrence happens occasionally, even when the cause of a blood vessel bursting in the eye is a simple cough or rub. About 1 in 10 people without risk factors have another episode; rates are higher with blood thinners, high blood pressure or diabetes. Frequent events warrant a medical review.
How to lower your chance of repeat episodes
You can’t prevent every episode, but you can cut the risk by protecting the eye’s surface and reducing brief pressure spikes that commonly trigger a subconjunctival haemorrhage. These simple steps target the usual causes of a blood vessel bursting in the eye.
- Keep blood pressure and diabetes controlled: regular checks and prescribed treatment.
- Lubricate dry eyes and don’t rub: use artificial tears for irritation.
- Be sensible with lenses: keep them clean, well‑fitting, and take breaks.
- Ease straining: manage coughs/allergies and avoid constipation and pushing on the toilet.
- Go easy on heavy lifting/bending: reduce Valsalva‑type strain where possible.
- Wear protective eyewear: for sport, DIY and dusty work.
- Don’t stop blood thinners yourself: see your doctor if bleeds are large or frequent.
- Get reviewed if episodes recur: to check for clotting issues or other causes.
What else could it be? Look-alike eye conditions to rule out
Most bright red eye patches are harmless subconjunctival haemorrhages, but a few conditions can look similar and need different management — especially if there’s pain, light sensitivity, discharge, vision change or a recent injury. If any of these apply, don’t assume the cause of a blood vessel bursting in the eye is to blame.
- Hyphema: Blood inside the front chamber of the eye (often after injury); usually painful and urgent.
- Corneal abrasion or infection: Sharp pain, tearing and light sensitivity; higher risk in contact lens wearers.
- Conjunctivitis (eye infection or allergy): Diffuse redness with discharge or itch rather than a flat blood patch.
- Significant eye trauma/foreign body: Pain, swelling or vision changes after a knock, cut or debris exposure.
On blood thinners: what to do if it keeps happening
If you’re on warfarin, aspirin or other blood thinners, a subconjunctival haemorrhage is more likely and often still harmless. Don’t stop your medication without medical advice. If the patches are large or keep recurring, get reviewed to check for contributing factors rather than assuming the cause of a blood vessel bursting in the eye is just “bad luck”.
- Call your prescriber: discuss recurrent episodes; if on warfarin, an INR check may be needed.
- Review other medicines: especially added painkillers that increase bleeding.
- Check blood pressure: and address cough, constipation or heavy lifting.
- Consider tests: recurrent or extensive bleeds may prompt clotting studies.
- Use lubricating drops and avoid rubbing.
- Seek urgent care: if there’s pain, vision change or blood inside the eye.
Contact lens wearers: safe steps after a burst vessel
Contact lenses add friction to an irritated surface, so give the eye a break while it heals. Follow these steps to prevent repeat episodes.
- Pause lenses: Wear glasses until the white looks normal and comfortable for 24–48 hours.
- Use lubricating drops: Preservative‑free artificial tears; avoid rubbing.
- Refresh hygiene: Replace torn lenses, clean/replace case, fresh solution every time.
- Seek care promptly for pain, light sensitivity or discharge (possible abrasion/infection).
Eye care in Randwick and the Eastern Suburbs
Based in Randwick, Bright Sight Eye Specialists provides comprehensive assessment of red eye and burst vessels, plus advanced cataract and retinal care for the Eastern Suburbs. Led by Moorfields‑trained Dr Rahul Dubey, we offer patient‑centred care, transparent pricing and no‑gap options for insured cataract surgery, with injections and laser available.
Key takeaways
Subconjunctival haemorrhage is common and usually harmless. It follows brief straining or friction and fades like a bruise. Know the red flags.
- Usually harmless: clears in 1–3 weeks; vision normal.
- Triggers: cough/sneeze/strain, rubbing, minor knocks, lens friction.
- Higher risk: 65+, hypertension, diabetes, blood thinners.
- See a doctor: pain, vision change, trauma, recurrence, discharge, or >2–3 weeks.
- Home care: artificial tears, no rubbing, pause lenses; don’t stop thinners yourself.
For timely advice or assessment in Randwick, contact Bright Sight Eye Specialists.