What causes blood vessels to burst in your eyes?

Sometimes, blood vessels burst in your eyes, which can be anything from a minor annoyance to a major health problem. This bleeding, called a subconjunctival hemorrhage, can result from trauma but can also happen without an obvious cause. It can even be a sign of a serious health issue, which makes blood vessels bursting in the eye a valuable warning sign for people with medical conditions.

What's going on in the eye?

Your eye is a complex bit of machinery, and a lot is happening under the surface, technically known as the conjunctiva.  The inside of your eye is filled with a jellylike fluid called the vitreous humor. This clear fluid helps the eye keep its shape and regulates the otherwise empty space between the lens, which focuses light, and the fovea, which picks up the image and sends it to the brain. 

The fovea is the little patch on the back of the eye with all the light-sensitive cells. This is where seeing happens. This area needs a constant blood supply, so there's a tangle of small blood vessels feeding it, but there's a catch. The human eye is inside-out, so instead of plugging the blood vessels into the back of the fovea and leaving the front clear to pick up light, our eyes do it backward. The blood vessels in the eye pop through the back and spread out on the inside of the eye cavity, then they flip around and plug into the fovea from the front. 

So, why aren't we all blind from having blood vessels blocking the view? Because we have brains that compensate for our eyes by editing out the blockage and kind of looking around the blood vessels like they're tall patrons sitting in front of the movie theater. We mentally work around the sight of our blood vessels. You can test this by looking at a bright blue sky during daylight hours. Don't look at the sun, obviously, but if the patch of sky is bright enough, you'll see little dark swimmies in your field of view. Those cells are inside the ocular blood vessels, moving through delicate little arteries and veins. Cool, right?

What's it like to have blood vessels burst in the eye?

As horrible as it sounds, blood vessels bursting in your eyes is usually not that bad — or at least, not painful. The blood vessels involved are tiny, and there aren't a bunch of pain receptors plugged into them, so a burst blood vessel isn't likely to knock the breath out of you like stubbing your toe.

It can be a real hassle, though. Sometimes, people wake up blind in one eye because all that blood pooled in the vitreous humor and is now stopping light from getting through. This is always something to talk to an eye care professional. Broken little blood vessels heal pretty quickly, and because the vitreous humor gradually recycles, you'll eventually (probably) get clear vision back without doing anything too drastic for treatment. You might be left with a little clot in the eye that floats around in there, which annoys some people but is harmless.

What causes blood vessels to burst in the eye?

Many things can trigger a subconjunctival hemorrhage. Still, some activities and conditions make this bleeding more likely, and there are ways to figure out what's going on if it happens to you.

Straining and eye pressure

Blood vessels burst when they can't contain the blood pressure inside them. Sometimes, this happens when there's a weakening in the wall of the vessel, and sometimes, it's because there's a spike in pressure. Or it could be a combination of the two. Do you know that feeling when you hold your breath and bear down, like a mother giving birth or a weightlifter trying to set a world record? That might make your muscles stronger, but it's at the cost of driving your blood pressure way up. Competitive weightlifters can get nosebleeds from the strain of lifting, for example. On occasion, the pressure of straining causes blood vessels to burst in your eyes, too.

Trauma and serious injury

Any injury can compromise blood vessels, especially tiny ones like those in your eyes. While your eyes are generally well, damage does happen. A swift blow to the front of your eye could cause damage, and a whiplash or blow to the back of your head could cause your corneas to detach. This is a common injury from car crashes, and it's no joke. If you suspect trauma has made your eyes bleed, get medical help immediately. It might be nothing, but it could also be something, and it's better to be safe with stuff like this.

Rubbing your eyes

You can accidentally inflict a minor injury on yourself if you've been rubbing your eyes. Anytime you press on the front of an eye, you're somewhat raising the pressure inside of it because of that vitreous humor. Even if you're being gentle with the rubbing, the increase in pressure, followed by a sudden drop when you take your hand away, could trigger a popped blood vessel. The back-and-forth motion of a too-vigorous rubbing could also set off a bleed, but this isn't common

Fatigue and eye strain

Everything can wear out if you strain it enough, and the blood vessels in your eyes are no exception. The human eye focuses by slightly stretching in or out, controlled by muscles attached to the sides. This little bit of flex lets you change the shape of the lens and get a longer or shorter focus, but it also puts a bit of strain on the rest of the eye. If you've been straining hard enough for long enough, you might get blood vessels bursting in one or both eyes. It can even happen hours later, such as when you stay up late studying and then go to bed.

Underlying medical conditions

Blood vessels can also burst for more concerning reasons. Sudden, otherwise unexplained blindness can signal medically dangerous high blood pressure, which makes the delicate little blood vessels in your eye the canary in the coal mine. It can also happen if you have uncontrolled diabetes because high blood sugar is like having little ninja stars circulating in your blood, damaging everything they touch

Preventing burst blood vessels in the eye

If your burst blood vessels were caused by an underlying medical condition, such as hypertension or diabetes, proper management should prevent eye problems. If you get blood vessels bursting because of fatigue and strain, be aware of your body's quirks and schedule rest periods more often. You could also reduce eye strain by getting the right glasses or contact lenses prescription.

Managing burst blood vessels

Despite our best efforts, sometimes your eye veins will pop. You're not helpless here, but treatment options are hit or miss.

Home remedies and self-care

The one surefire home remedy for burst blood vessels in the eye is to wait. In most cases, if you're otherwise healthy, the problem eventually disappears. If you'd like it to go away faster, you can rest with a cold compress over your eyes for a few minutes or more daily. Try to avoid strain in general, especially while you're recovering.

Over-the-counter remedies

It’s best to keep your eyes moist and lubricated during healing. Over-the-counter drops and artificial tears can handle that for you. They're also helpful if the blood vessels burst outside the whites. Regular drops in the eye can reduce redness and keep the irritation under control. Some drops are just saline, with no medication, while others have active medical agents. Regardless of which one you're using, it's always a good idea to check in with an eye care professional before starting a treatment course like this. Remember to inform the medical or pharmacy staff about any other meds you might be using because there could be an unexpected interaction.

Professional care

If the condition is serious enough to send you to the clinic for professional treatment, your eye care professional might have a few tricks to help you. Some clinics do laser ablation, which uses advanced technology to harmlessly zap blood clots away and even cauterize problem blood vessels. You might also have some surgical options, depending on your underlying conditions and the severity of the bursting blood vessel issue for you.

Blood vessels bursting: a surprisingly manageable problem

Blood vessels burst for various reasons, but you can reduce your risk by staying healthy and managing underlying medical issues. One way to do just that is to get regular eye exams and follow the advice of your eye care professionals.

FAQ

Are burst blood vessels in the eyes a serious condition?

Most of the time, a subconjunctival hemorrhage is not serious, and you don't need treatment. For peace of mind, you can bring it up with your eye care professional.

When should I seek medical attention for burst blood vessels in my eyes?

You may need medical attention if the burst blood vessel doesn't go away on its own in 14-21 days, if it's accompanied by pain, or if you have vision loss in that eye.

Can burst blood vessels in the eyes indicate an underlying health issue?

You're more likely to get burst blood vessels in the eye if you have diabetes, high blood pressure, or several other conditions. It can still happen even if you're otherwise healthy, such as when you cough or sneeze hard. Only your eye care professional can properly diagnose a medical condition by examining your eyes.