Blood in the Eye: What Is a Subconjunctival Hemorrhage?

A subconjunctival hemorrhage is another term for blood in the eye. Bleeding inside the eye can result in a speck of redness or a large area of red blood. The hemorrhage looks like a patch of bright, red blood on the white part of your eye.

While waking up to a bleeding eye can be scary, a subconjunctival hemorrhage is usually harmless. The visible blood typically results from a popped blood vessel in the eye.

In this article, you'll learn what can cause blood in your eye, symptoms to pay attention to, and ways to treat it.

Symptoms of Subconjunctival Hemorrhage

The sclera (white part of your eye) is covered by a thin, clear tissue called the conjunctiva. The conjunctiva also lines the inside of your eyelid and houses a network of small, thin blood vessels.

These small blood vessels are fragile and can easily pop or break. The popped blood vessel in your eye will then cause blood to leak out and settle between the conjunctiva and the sclera.

If the leak is small, a part of your eye may be slightly or even bright red, as seen in this picture of a relatively minor subconjunctival hemorrhage.

But if the leak is large enough, the entire white part of your eye may look blood-red, as in this picture of a more substantial subconjunctival hemorrhage. In some cases, the eye may bulge outward.

When to Be Concerned About Bleeding in the Eye

Call your doctor if you:

• Notice the subconjunctival hemorrhage lasts more than three weeks
• Have eye pain
• Experience vision loss
• Have a history of eye injury or recurring subconjunctival hemorrhage
  

Causes of Blood in the Eye

An eye injury usually causes bleeding of the eye. Less common but serious causes of eye bleeds include:

• Cancer
• Malformations of blood vessels in the eye
• Irritation and inflammation of the iris (the colored part of the eye)

Small amounts of bleeding in thee ye can result from forcefully sneezing or coughing. Other risk factors are high blood pressure and taking certain medications that alter the way your blood clots.

A subconjunctival hemorrhage can be caused by:

• Trauma
• Hard coughing
• Hard sneezing
• Vomiting
• Heavy lifting
• Forceful hand rubbing of the eye
• Strain caused by constipation
• Various eye infections

Occasionally, a subconjunctival hemorrhage can be a warning sign for one of the following related conditions:

• Diabetes
• Hypertension (high blood pressure)
• Bleeding or blood disorders
• Leukemia
• Sickle cell disease

Diagnosis

Schedule an eye exam if you're concerned about blood in your eye. During the eye exam, the optometrist or ophthalmologist (eye doctor) will:

• Complete a careful medical history to rule out potential causes of the hemorrhage
• Examine your eyes to ensure the eye is intact
• Check that other injuries haven't occurred to other structures of the eye
• Measure your eye pressure
• Dilate your eyes so they can look inside and ensure there's no trauma or bleeding deep inside the eye

It's important to have your optometrist or ophthalmologist examine the hemorrhage to identify a cause and rule out other possible health conditions.

Subconjunctival Hemorrhage Treatment

Try to remain calm if you suddenly notice blood inside your eye. Visible blood in your eye due to subconjunctival hemorrhage will be slowly reabsorbed by your body. Most cases resolve within seven days without treatment.

However, a large subconjunctival hemorrhage can take up to three weeks to go away. The redness may turn to a brown color, then yellow, and then white again. The blood will not stain your eye.

You may apply over-the-counter artificial tears to reduce any scratchiness.

A Word From Verywell

Even though the appearance of blood in your eye can be disturbing, it's usually no cause for alarm, especially if you don't have any pain or vision changes.

Many people arrive at their doctor's office with a subconjunctival hemorrhage without recalling any trauma, circumstance, or underlying medical problem. In many cases, the popped blood vessel in the eye is caused by a blow to the eye with a hand in the middle of the night while sleeping.

However, if you experience a subconjunctival hemorrhage more than twice in one year, that may cause concern, and you should get a full medical checkup.