Spotting a bright red patch on the white of your eye can be confronting. In most cases, it’s a subconjunctival haemorrhage — a tiny burst blood vessel under the clear surface layer (the conjunctiva). Think of it like a bruise on the eye: it often follows a cough, sneeze or minor knock, usually doesn’t hurt, and rarely affects vision. The colour can look dramatic because the blood is trapped on the surface, but the eye itself is typically unharmed and the mark fades as your body reabsorbs the blood.
This guide explains what causes a broken blood vessel in the eye, who’s more likely to get one, and what you will — and won’t — feel. You’ll learn how long it lasts, how healing changes the colour, and how to tell it apart from other red-eye conditions that do need treatment. We’ll cover when to seek urgent care, the links with blood pressure, medicines and stress, simple steps to feel more comfortable at home, and special situations like contact lenses, children, pregnancy and after eye surgery.
Common causes of a broken blood vessel in the eye
Most subconjunctival haemorrhages happen when a tiny surface vessel gives way after a brief spike in pressure or minor surface trauma. Everyday actions that raise venous pressure — or small knocks you might not remember — are the typical broken blood vessel eye cause. Often there’s no pain and no clear trigger, and many cases are idiopathic.
- Coughing, sneezing or vomiting: Momentary straining can burst a fragile vessel.
- Straining on the toilet or lifting/pushing heavy loads: Short-lived pressure surges are enough.
- Bending forward vigorously: Can transiently increase pressure in head and eye veins.
- Rubbing the eye hard: Mechanical friction can split a tiny capillary.
- Minor bumps or pokes to the eye: Even slight trauma can do it.
- Contact lens handling/use: Dryness and friction raise the chance of a surface bleed.
Risk factors and medicines that raise your risk
Some people are more prone to a subconjunctival haemorrhage. Fragile surface vessels, systemic conditions and certain medicines all make a small pressure spike or minor rub more likely to end in a red patch. If you have any of the following, a broken blood vessel eye cause may be easier to trigger.
- Age 65+: higher risk of subconjunctival haemorrhage.
- High blood pressure (hypertension).
- Diabetes.
- Blood thinners/antiplatelets (e.g., warfarin, aspirin) and interferon.
- Blood‑clotting disorders (e.g., haemophilia, von Willebrand disease).
- Contact lens wear, dryness or friction.
- Recent eye surgery or eye injury.
What you will (and won’t) feel or notice
With a broken blood vessel in the eye (subconjunctival haemorrhage), the standout sign is a sharply defined, bright red patch on the white of the eye. It usually causes no pain, no discharge and no change in vision. Many people only notice it in the mirror. You might feel mild grittiness, itch or surface irritation from dryness, but not true soreness or light sensitivity. If you do notice pain, light sensitivity, discharge or blurred vision, that’s not typical and warrants prompt assessment.
How long it lasts and what healing looks like
Most subconjunctival haemorrhages clear on their own within about one to two weeks; some fade in just a few days, while larger patches can take a few weeks. As the blood is reabsorbed, the colour changes — typically bright red to brown and then yellow — much like a fading bruise. There’s no way to speed this up, though lubricating drops can ease any surface irritation. If the red patch hasn’t resolved within 2–3 weeks, keeps recurring, or you develop pain or vision changes, arrange a medical review to check for contributing factors such as high blood pressure, medications or a bleeding tendency.
Subconjunctival haemorrhage versus other causes of a red eye
Not every red eye is a broken blood vessel. A subconjunctival haemorrhage typically shows as a sharply edged, bright red patch on the white of the eye, with no pain, discharge or change in vision. Other causes of red eye tend to look more diffuse and often come with discomfort, sensitivity to light, discharge or blurred vision. These features help you tell a harmless surface bleed from problems that need treatment.
- Subconjunctival haemorrhage: Bright, flat, well‑defined red patch; no pain, discharge or vision change.
- Conjunctivitis (infection): Redness with discharge and irritation rather than a single sharp patch.
- Hyphema (blood in front of the iris): Eye pain and vision disturbance; needs urgent assessment.
- After eye injury: Redness plus pain or vision change suggests deeper damage — get checked promptly.
When to seek urgent medical care
A subconjunctival haemorrhage is usually harmless, but don’t ignore a red eye if something doesn’t feel right. More serious problems can mimic a simple broken blood vessel, and timely care protects sight. Seek same‑day assessment if you notice any of the following.
- Recent eye or head injury: Even a minor poke or blow warrants prompt review, especially with other symptoms.
- Eye pain, light sensitivity or blurred vision: Not typical of a surface bleed and may signal hyphema or another condition.
- Blood in front of the iris/pupil (pooling at the bottom): Needs urgent care.
- Red patch not clearing in 2–3 weeks: Or if episodes keep recurring.
- Frequent bleeding or easy bruising: Especially if you take blood thinners or have a bleeding disorder — arrange a prompt medical check.
Is it linked to high blood pressure, stroke or stress?
High blood pressure is a recognised risk factor for a subconjunctival haemorrhage, and brief spikes from coughing, sneezing or straining commonly trigger it. On its own, a broken blood vessel in the eye is not a sign of stroke and most cases are harmless; recurrent episodes should prompt a GP check (including blood pressure and medicines). Psychological stress isn’t a proven direct cause — it’s the physical straining (vomiting, heavy lifting, constipation) or minor eye trauma/rubbing that typically makes a surface vessel burst.
What you can do at home to feel more comfortable
There’s no treatment that speeds up a subconjunctival haemorrhage, but simple care can ease irritation while it heals. Focus on keeping the surface of the eye comfortable and avoiding extra friction or pressure. The red patch will fade on its own over days to a couple of weeks, and most people can continue normal activities.
- Artificial tears: Use preservative‑free lubricating drops as needed to soothe any grittiness or itch.
- Hands off: Avoid rubbing or pressing on the eye; this reduces further surface irritation.
- Pause contact lenses: If you wear contacts and the eye feels irritated, switch to glasses until it settles.
- Take it easy on strain: Carry on as normal but try to avoid heavy straining or very heavy lifting for a few days.
How doctors diagnose it and rule out other causes
Doctors usually diagnose a subconjunctival haemorrhage by looking at the eye and taking a brief history (recent cough/strain, rubbing, minor trauma, contact lenses or surgery). They’ll check vision, pupils and often examine the eye with a slit‑lamp to confirm the blood is on the surface (not a hyphema). Blood pressure is commonly measured. If episodes recur or bruising is easy, they’ll review medicines (e.g., blood thinners) and consider tests for clotting disorders, diabetes and hypertension.
Prevention tips to reduce recurrences
You can’t always prevent a subconjunctival haemorrhage, but you can lower the odds of repeat episodes by tackling triggers and underlying risks. Reduce the common broken blood vessel eye causes — rubbing and straining — and keep systemic factors such as blood pressure and diabetes well controlled. Comforting the eye surface also helps.
- Check and treat high blood pressure with your GP.
- Review blood thinners/aspirin; never stop without advice.
- Ease straining: manage constipation and cough; avoid heavy lifts.
- Hands off: avoid rubbing; use artificial tears for dryness.
- Contact lens hygiene and breaks to minimise friction.
- Protective eyewear for sport, tools and dusty work.
- Manage diabetes and attend regular eye checks.
Special situations: contact lenses, children, pregnancy and after eye surgery
Contact lenses can be a broken blood vessel eye cause when dryness or friction irritates the conjunctiva; pause wear until the eye is white and comfortable, and have lens fit/hygiene reviewed if episodes recur. In children, it often follows coughing, sneezing, rubbing or a minor bump; any pain, light sensitivity, vision change or head/eye injury warrants prompt review. During pregnancy and after delivery, straining (labour, constipation) can trigger a patch; discuss with your GP/midwife and check blood pressure if recurrent. After eye surgery (e.g., cataract), small surface bleeds are more likely and usually settle within weeks—report pain or vision symptoms.
Frequently asked questions
Got questions about that sudden red patch? Here are fast answers on what it means, what to do, and when to get help. Most cases heal quietly while you get on with your day; if anything feels unusual, book a check.
- Is it painful or dangerous? Usually painless and harmless; get care for pain, light sensitivity or blurred vision.
- Do I need treatment or antibiotics? No — it clears on its own; artificial tears only for comfort.
- Why does it keep happening? Recurrences occur; have blood pressure and medicines reviewed.
Key takeaways
A subconjunctival haemorrhage looks dramatic but is usually a harmless surface “bruise” caused by brief straining (cough, sneeze, lifting) or minor rubbing/trauma. It’s typically painless, doesn’t affect vision and clears on its own in one to two weeks as the colour fades from red to yellow. Repeated episodes or slow healing deserve a medical check to look for contributing factors.
- Typical look: Bright, sharply edged red patch on the white of the eye.
- Usually no symptoms: No pain, discharge or blurred vision.
- Common triggers: Coughing, sneezing, straining, rubbing, minor knocks.
- Risk factors: High blood pressure, diabetes, blood thinners, contact lenses, recent eye surgery.
- When to act: Pain, light sensitivity, vision change, recent injury, or no improvement in 2–3 weeks.
- Comfort care: Artificial tears, avoid rubbing, ease straining; lenses off until settled.
Need expert reassurance or a same‑day assessment in Sydney’s Eastern Suburbs? Book with Bright Sight Eye Specialists.