A burst blood vessel in the eye: when a red patch is harmless and when to check
A bright red patch on the white of a parent's eye looks alarming and is usually harmless. Here is what it is, how long it takes to fade, what triggers it, and the signs that mean an eye doctor should look.
See an eye doctor the same day if…
I see parents and grandparents for squint, cataract and everyday eye problems, so one family can keep one eye doctor. Family eye care Where I practise
- A burst blood vessel on the white of the eye is a small bleed under the clear surface layer (subconjunctival haemorrhage). The AAO says it is usually harmless and often heals on its own.
- Most cases fade within one to two weeks, changing from bright red to deeper red to yellow-green (StatPearls).
- Coughing, sneezing, straining and rubbing the eye are the commonest triggers (AAO). Diabetes, high blood pressure and medicines that make you bleed more easily are less common causes.
- If you take a blood thinner, do not stop it yourself. Ask the doctor who prescribed it.
- Pain, a change in vision, an injury, repeated bleeds, or bleeding or bruising elsewhere mean an eye doctor should look.
A bright red patch on the white of a parent's eye looks alarming, and usually it is not. This page explains what a burst blood vessel in the eye is, how long it takes to fade, what can set it off, and the signs that mean an eye doctor should look.
It is written for the adult with the red patch and for the son or daughter who is worried about them. The patch is a symptom of a small bleed on the surface. It is not a diagnosis of anything serious.
What is a burst blood vessel in the eye?
It is a small bleed under the clear skin that covers the white of the eye. The medical name is subconjunctival haemorrhage (the American spelling is hemorrhage). The American Academy of Ophthalmology (AAO) says the conjunctiva contains many tiny blood vessels that can break, and when they do, blood leaks between the conjunctiva and the white of the eye, the sclera. That blood is the bright red spot.
It is a bleed on the surface, not inside the eye. StatPearls, a clinical reference, says it comes from small superficial vessels over the sclera rather than from deeper structures. That is why vision is not affected.
Why does it look so alarming when it is usually harmless?
Blood spread under a thin clear layer looks vivid, and the patch can seem to cover a lot of the white even when the amount of blood is small. The AAO says these blood spots can look scary but a subconjunctival haemorrhage is usually harmless and often heals on its own. Usually the only symptom is the red spot, and you may not know it is there until you look in the mirror. Sometimes there is very mild irritation.
StatPearls adds what the condition does not cause: no pain, no sensitivity to light, no drop in vision and no change in the pupils. Those missing features help doctors tell it from more serious eye problems. The action: if the eye is comfortable, sees normally and the patch is the only thing, it is reasonable to watch it and use the checklist below.
How long does it take to fade?
Usually one to two weeks, though a larger patch can take longer. The AAO says it should heal on its own, in a few days to a few weeks depending on the size.
StatPearls says most cases resolve within one to two weeks, and that the patch changes colour as it goes: bright red first, then a deeper red, and finally a yellow-green tint as the blood is broken down. MedlinePlus says no treatment is needed, that it most often goes away in about 2 to 3 weeks, and that the white of the eye may look yellow as it clears.
That colour change is the normal way it clears, like a bruise on the skin, and it is not a sign of a new problem. If the eye feels irritated, the AAO says artificial tears may be used. No other treatment is needed in the usual case.
What can set off a burst blood vessel in the eye?
Most often a brief rise in pressure in the veins. The AAO says coughing, sneezing, straining or similar actions most commonly cause it, because they briefly raise the blood pressure in the veins and a capillary can break. An injury to the eye can cause it too, and the AAO notes that even rubbing the eyes too hard might.
Less common causes in the AAO list are diabetes, high blood pressure, and medicines that make you bleed more easily. StatPearls says older adults with high blood pressure or diabetes face the greatest risk, while younger people more often have an injury or no clear cause. In many people no trigger is found at all.
What about blood thinners and blood pressure?
Both can make a bleed more likely, and both are worth mentioning to the doctor who looks after them. The AAO lists aspirin and blood-thinning medicines among the things that can make you bleed easily, and high blood pressure among the less common causes. If you take a blood thinner and a patch appears, do not stop or change the medicine yourself. Ask the doctor who prescribed it, because stopping a medicine they have started for a reason can carry its own risk.
If you have high blood pressure or diabetes and have a red patch, it is a good prompt to check that those are being followed up. The patch itself does not mean the blood pressure is out of control. It is a prompt to ask, not a diagnosis.
When should an eye doctor look at it?
Go the same day if the eye is painful, if the vision changes, or if the bleed followed an injury. StatPearls says it does not normally cause pain or reduced vision, so those signs mean something else may be going on.
The NHS, writing about red eyes in general, advises urgent help if the eye is very painful and red, if there is any change in sight such as flashing or loss of vision, if it hurts to look at light, or after an injury to the eye or something stuck in it.
See an eye doctor soon, not necessarily the same day, if the bleeds keep coming back. The AAO says if you get them often, your ophthalmologist will talk with you about further testing, and StatPearls says recurrent cases need investigation to exclude a body-wide or structural cause.
Also see a doctor if you notice bleeding or bruising elsewhere, such as easy bruising, nosebleeds or bleeding gums, because the AAO notes that rarely a clotting problem or another blood problem is the cause. The NHS also says to see a GP or optician if a red patch in the eye lasts more than a few days or you are worried.
For a red, uncomfortable eye that is not a patch but gritty or dry, see dry, gritty eyes in parents and grandparents. For flashes or new floaters, which are a different matter, see sudden floaters and flashes in a parent.
What should the family do?
Look at the eye together. Check that the patch is the only change, that the eye is not sore and that the vision is normal, then note the date it appeared so you can tell how long it lasts. Try to avoid rubbing the eye. If a parent is on a blood thinner, keep the prescriber informed. For a map of who in the household needs which eye check, see eye checks for the whole family. This page is general information and does not replace an examination.
- The eye is painful, or it hurts to look at light.
- Vision changes: blurring, flashing, wavy lines or loss of vision.
- The bleed followed a knock or an injury to the eye, or something is stuck in it.
- The whole eye is very dark red, or one pupil looks bigger than the other.
Common questions
Is a burst blood vessel in the eye serious?
How long does a burst blood vessel in the eye take to go away?
What causes a burst blood vessel in the eye?
Does a burst blood vessel mean my blood pressure is high?
I take a blood thinner. Should I stop it because of the red patch?
Is there treatment for a burst blood vessel in the eye?
When should I see an eye doctor about a burst blood vessel?
- American Academy of Ophthalmology · What is a subconjunctival hemorrhage? · www.aao.org
- StatPearls · Subconjunctival Hemorrhage (Zeppieri, Noohani), record via Europe PMC · europepmc.org
- NHS · Red eye · www.nhs.uk
- MedlinePlus (US National Library of Medicine) · Subconjunctival hemorrhage · medlineplus.gov