Blood in the eye usually comes from a broken blood vessel on the surface of the eye, which looks alarming but is almost always harmless. Less commonly, bleeding can occur deeper inside the eye from trauma, disease, or medications, and these cases are more serious. The cause depends on exactly where the blood is and how it got there.
Types of Eye Bleeding
Not all eye bleeding is the same. The location of the blood inside the eye tells you a lot about what happened and how urgent it is.
A subconjunctival hemorrhage is the most common type. It’s a broken blood vessel in the white of the eye (the sclera), and it creates a bright red patch that can look dramatic but causes no pain and no vision changes. Think of it like a bruise, just in a place where you can see it clearly.
A hyphema is bleeding into the front chamber of the eye, the fluid-filled space just in front of the colored part (iris). Unlike a surface bleed, a hyphema causes pain and can interfere with vision. It typically results from a direct blow to the eye. The blood pools visibly in front of the iris, sometimes settling into a visible layer at the bottom of the eye.
A vitreous hemorrhage is bleeding into the gel that fills the center of the eyeball. You can’t see this type from the outside. Instead, it shows up as sudden floaters, hazy vision, or a reddish tint to your sight. This type is often linked to diabetes or other conditions affecting the blood vessels at the back of the eye.
Everyday Physical Triggers
The most common cause of a red patch on the white of your eye is a sudden spike in pressure through the tiny, fragile blood vessels on the eye’s surface. Anything that makes you strain, hold your breath, or bear down can do it. Doctors call this a Valsalva maneuver, but in practical terms it includes coughing, sneezing, vomiting, heavy lifting, and straining during a bowel movement. The sudden increase in venous pressure can rupture the delicate conjunctival vessels.
Rubbing your eyes too hard, wearing contact lenses, or even sleeping in an awkward position can also trigger a surface bleed. In younger people, the most common cause is minor trauma to the eye. Many people wake up with a subconjunctival hemorrhage and never identify the exact trigger, which is normal.
High Blood Pressure and Diabetes
In adults over 50, high blood pressure is the leading systemic cause of subconjunctival hemorrhage. Chronically elevated blood pressure puts extra stress on small blood vessels throughout the body, including the ones in your eyes. If you’re getting repeated episodes of blood in the white of your eye without an obvious trigger like coughing or injury, it may be a sign your blood pressure needs attention.
Diabetes damages small blood vessels over time, making the ones in the eye more fragile and prone to breaking. This accounts for surface bleeds in older adults, but diabetes also drives a more dangerous process deeper in the eye. In advanced diabetic retinopathy, high blood sugar damages the tiny vessels that nourish the retina, cutting off its blood supply. The eye responds by growing new blood vessels, but these replacement vessels are poorly formed. They leak and bleed easily, sometimes spilling blood into the vitreous gel at the center of the eye. This is one of the most common causes of vitreous hemorrhage and can lead to significant vision loss if untreated.
Trauma and Injury
A direct blow to the eye is the most common cause of hyphema. Sports injuries, falls, car accidents, and even minor impacts like being hit by a ball or an elbow can do it. The force compresses the eyeball rapidly, creating shearing forces that tear the small blood vessels around the iris and the muscles that control it. Red blood cells then accumulate in the front chamber of the eye.
Even a small hyphema visible only under magnification (called a microhyphema) needs medical evaluation because the blood can block the eye’s drainage system and raise pressure inside the eye. Larger hyphemas carry a risk of rebleeding in the days after injury, which can cause further complications.
Blood-Thinning Medications
If you take blood thinners, you have a higher risk of bleeding inside the eye. An analysis of the World Health Organization’s global drug safety database found a strong link between intraocular hemorrhage and both older blood thinners like warfarin and newer ones like rivaroxaban, dabigatran, and apixaban. The researchers identified hundreds of cases of deep eye bleeding (vitreous, retinal, and choroidal hemorrhage) tied to these medications.
Warfarin showed the strongest association with choroidal hemorrhage (bleeding behind the retina), while rivaroxaban had the highest association with retinal and vitreous hemorrhage. This doesn’t mean you should stop taking a prescribed blood thinner, but it does mean any new eye bleeding while on these medications deserves a prompt call to your doctor. Aspirin and other over-the-counter anti-inflammatory drugs can also make surface bleeds more likely or slower to resolve.
What Healing Looks Like
A subconjunctival hemorrhage follows a predictable pattern. The bright red patch slowly changes color over the course of one to two weeks, fading through shades similar to a healing bruise. Toward the end, the white of your eye may take on a yellowish tint before returning to normal. Larger spots can take longer. No treatment speeds up the process, though cold compresses in the first day or two and artificial tears for any mild irritation can help with comfort.
Deeper bleeding inside the eye, like a hyphema or vitreous hemorrhage, has a more variable timeline and usually requires monitoring by an eye specialist. Recovery depends on the amount of blood, the underlying cause, and whether complications like elevated eye pressure or retinal damage develop.
Signs That Need Prompt Attention
A painless red spot on the white of your eye with normal vision is almost certainly a simple subconjunctival hemorrhage and will clear on its own. But certain symptoms alongside eye bleeding signal something more serious:
- Eye pain: Surface bleeds don’t hurt. Pain suggests deeper bleeding, elevated eye pressure, or injury to internal structures.
- Vision changes: Blurriness, floaters, a reddish tint, or any loss of vision points to bleeding inside the eye rather than on the surface.
- Recent eye injury: Any trauma to the eye that causes visible bleeding warrants an exam to rule out hyphema or damage to deeper structures.
- Recurring episodes: Frequent subconjunctival hemorrhages or easy bruising elsewhere on the body may indicate an underlying bleeding disorder or uncontrolled blood pressure.