A stroke in the eye occurs when blood flow to the retina is blocked. Treatment depends on the type of blockage and the severity of the damage. Early medical care improves outcomes.

Blood vessels carry vital nutrients and oxygen to every part of the body. When they narrow or become blocked by a blood clot, the blood supply is cut off, causing a stroke.

In the case of an eye stroke, the blockage affects the retina. The retina is the thin film that lines the inner surface of the back of your eye. It sends light signals to your brain so it can understand what your eyes see.

When the retinal veins are blocked, fluids leak into the retina. This causes swelling and prevents oxygen from circulating, which impacts your ability to see. When blood flow to the retina is completely interrupted, severe damage to the eye can occur.

An obstruction in your main retinal vein is called a central retinal vein occlusion (CRVO). When it happens in one of your smaller branch veins, it’s called a branch retinal vein occlusion (BRVO). If it affects the central retinal artery, it’s known as central retinal artery occlusion (CRAO). CRAO can be the most severe of the three.

Symptoms of eye stroke can develop slowly over hours or days, or they can come on suddenly. They also depend on which blood vessel is obstructed and whether you have CRVO, BRVO, or CRAO.

The biggest sign it may be a retinal stroke is if you experience symptoms in one eye only.

The severity of vision loss and the area of the vision field affected may depend on the region of the retina involved in the blood flow blockage. A blockage in the central artery often leads to more severe symptoms and central vision loss.

Symptoms of CRVO and BRVO may include:

  • Floaters: These may appear as small gray spots floating around in your field of vision.
  • Blurred vision: You may see your vision steadily worsen in one side or all of the vision field.
  • Vision loss: You may experience vision loss gradually or suddenly, and it may be subtle to severe.
  • Pain or pressure: Though eye strokes are often painless, severe cases of CRVO may cause localized pressure or discomfort in the affected eye.
  • Bleeding: Your retina may appear red or have blood spots throughout.

The most common CRAO symptom is partial or complete central vision loss. It may mimic a black curtain coming down in front of your eye. The retina may appear pale and have a cherry red spot. CRAO is the eye equivalent of an ischemic cerebrovascular accident.

The extent of the damage depends on how long the blood flow blockage lasts. The longer the interruption of blood flow, the greater the damage and the more severe the symptoms will be.

These symptoms of eye stroke are a medical emergency, even if you think they’re improving after a few minutes. Without adequate and prompt treatment, an eye stroke may lead to permanent vision loss.

Eye strokes are sometimes early signs of other vascular events, including ischemic strokes and heart attacks.

Obstructed blood flow that affects the retina causes an eye stroke. The interruption of blood flow is usually due to the narrowing of the blood vessels because of fatty plaque buildup or a blood clot.

It’s not always clear why eye stroke occurs, but certain health conditions, such as high blood pressure and diabetes, may increase your risk.

Anyone can have an eye stroke, but certain factors make it more likely. For example, an eye stroke may be more common in older adults and men.

Certain medical conditions also increase your risk of eye stroke. These include:

Tobacco use also increases the chance of having any type of stroke.

An eye or emergency doctor may start by examining your eyes. They may use an ophthalmoscope, also called a fundoscope, to take a detailed look inside your eye. They will also want to have a description of your symptoms.

Other diagnostic testing may include:

Since eye symptoms may be caused by an underlying condition, you may also be tested for:

If you’ve already received a diagnosis of one of these conditions, the doctor may consider this when establishing your treatment for an eye stroke.

Read about vision loss after an ischemic stroke.

Your treatment will depend on the severity of the stroke damage. Another consideration is your overall health. Some possible therapies include:

The sooner you start treatment for an eye stroke, the better your chances of preserving your vision. Any other conditions that may cause blood clots also need to be treated.

You can recover from an eye stroke, particularly if you receive treatment shortly after the first signs. But some complications are still possible, including:

  • Macular edema or inflammation of the macula: The macula is the middle part of the retina that helps with sharpness of vision. Macular swelling may blur your vision or lead to vision loss.
  • Neovascularization: With this condition, new and abnormal blood vessels develop in the retina. These blood vessels can leak into the vitreous (the liquid inside the eye) and cause floaters. In severe cases, the retina can become completely detached.
  • Neovascular glaucoma: This painful increase in pressure in the eye is due to the formation of new blood vessels.
  • Blindness: A complete and permanent loss of vision is possible with a severe eye stroke, particularly those that don’t get medical care in time.

Because of the potential for serious complications from an eye stroke, follow-ups with a doctor are highly recommended. You may need monitoring of your eye health for a year or longer. A doctor will want to know of any new and persistent symptoms.

You’ll also need to monitor other health conditions that can affect your eyes. If you have heart problems or diabetes, following medical recommendations is essential. A healthcare team may recommend a nutrient-dense diet, regular physical activity, and weight management.

If it’s been compromised, you may start to regain your vision after an eye stroke, but this may not be a complete recovery. Some eye stroke cases may lead to permanent vision loss.

Eye stroke results from an interruption in the blood flow to a region of the eye. It occurs on one side only and may lead to blurred vision, floaters, pressure, and vision loss.

Early treatment may improve outcomes. Eye stroke is a medical emergency and immediate care is encouraged as soon as you notice the first symptoms.