What Causes A Cyst Behind The Eye? Why It Happens

A cyst behind the eye is a fluid-filled sac that forms in the space just behind your eyeball. This area is called the orbit, and it holds your eye, muscles, nerves, and fat. When a cyst develops here, it pushes on these structures. The most common cause is a blocked oil gland or a buildup of fluid from nearby sinuses. But there are other reasons, and most are not serious.

What Exactly Is a Cyst Behind the Eye?

A cyst behind the eye is not the same as a stye or a pimple on your eyelid. Those are on the surface. A cyst behind the eye sits inside the bony socket that holds your eyeball. It can be as small as a pea or as large as a marble.

These cysts are usually benign, meaning they are not cancer. They form when a gland gets blocked or when tissue collects fluid. The body sometimes walls off the fluid with a thin membrane, creating a sac. Over time, the sac can grow as more fluid builds up.

Your eye doctor can often see a cyst behind your eye using imaging tests. An MRI or CT scan gives a clear picture of the orbit. Ultrasound can also help, especially for cysts near the front of the eye socket.

What Causes a Cyst Behind the Eye?

The causes fall into a few clear categories. The most common is a dermoid cyst. This is a type that forms before birth. Skin cells get trapped inside the orbit during fetal development. These cysts grow slowly and may not cause problems until adulthood.

Mucoceles are another common cause. These cysts come from the sinuses, the air-filled spaces around your nose and eyes. When a sinus opening gets blocked, mucus builds up and pushes into the orbit. Research published in the journal Orbit found that sinus-related mucoceles account for about 15 percent of all orbital cysts.

Epidermoid cysts form from blocked oil glands in the eyelid or skin around the eye. These are similar to the cysts people get on their face or back. They are usually harmless but can grow large enough to press on the eye.

Less common causes include cholesterol granulomas, which form after trauma or bleeding in the orbit. Hydatid cysts are rare and caused by a parasitic infection, though these are extremely uncommon in the United States.

Does a Cyst Behind the Eye Cause Symptoms?

Not always. Many people with a cyst behind the eye have no symptoms at all. The cyst is found by accident during an eye exam or imaging for something else. But when symptoms do appear, they are usually related to pressure.

The most common symptom is bulging of the eye, called proptosis. The eyeball gets pushed forward. You might notice your eye looks different in the mirror or that one eye seems more prominent than the other.

Other symptoms include double vision, pain when moving the eye, or a feeling of pressure behind the eye. Some people report headaches or a dull ache on one side of the face. If the cyst presses on the optic nerve, you might notice blurry vision or loss of side vision.

According to the American Academy of Ophthalmology, any new bulging of one eye should be checked by a doctor. Even if there is no pain, a change in eye position needs evaluation.

How Is a Cyst Behind the Eye Diagnosed?

Diagnosis starts with a complete eye exam. Your doctor will check your vision, eye movement, and how your eyes line up. They will also look at the front of your eye and measure eye pressure.

Imaging is the key to diagnosis. An MRI gives the best view of soft tissues like cysts. It shows the size, shape, and exact location of the cyst. A CT scan is better for seeing bone and can show if the cyst has eroded into the sinus.

Sometimes your doctor will order an ultrasound. This is quick and does not use radiation. It works well for cysts near the front of the orbit.

In rare cases, a biopsy is needed. A small sample of fluid or tissue is taken with a needle. This is done only when imaging cannot tell if the cyst is benign or if there is concern for something more serious.

The table below compares the main imaging methods:

What Treatment Options Are Available?

Treatment depends on the type of cyst, its size, and whether it causes symptoms. Many cysts do not need treatment at all. Your doctor may recommend simply watching it over time.

If the cyst is small and causes no symptoms, observation is safe. You get periodic imaging to check for growth. Most cysts stay the same size or grow very slowly. Some even shrink on their own.

Surgery is the main treatment when a cyst causes symptoms. The goal is to remove the cyst completely without damaging the eye or surrounding structures. This is done by an oculoplastic surgeon, a specialist in the area around the eye.

Surgical approaches vary. For cysts near the front, the surgeon makes a small incision in the eyelid or through the skin near the eyebrow. For deeper cysts, the approach may be through the sinus or behind the eye. Recovery time depends on the size and location of the cyst.

Drainage is an option for some cysts, but it has a higher chance of the cyst coming back. The fluid is removed with a needle, but the sac wall stays behind. The sac can refill over weeks or months.

Endoscopic surgery is used for sinus-related mucoceles. A thin tube with a camera goes through the nose into the sinus. The surgeon opens the blocked sinus and drains the mucocele. This avoids any incision on the face.

What to Avoid and Common Misconceptions

There are several myths about cysts behind the eye that need clearing up. First, you cannot pop a cyst behind your eye. Unlike a pimple, these cysts are deep inside the socket. Trying to squeeze or press on them can cause serious damage to the eye or optic nerve.

Second, warm compresses do not work for cysts behind the eye. Warm compresses help with surface styes and chalazia on the eyelid. But they cannot reach a cyst deep in the orbit. Do not waste time with home remedies for this condition.

Third, most cysts behind the eye are not cancer. The vast majority are benign. Cancerous tumors in the orbit are rare. Still, any new growth needs evaluation to be sure.

Fourth, eye strain does not cause cysts. Reading, screen time, or wearing the wrong glasses do not create cysts. Cysts have specific physical causes like blocked glands or congenital tissue.

Here is a quick list of what to avoid:

• Do not press or massage the eye area
• Do not use warm compresses expecting results
• Do not ignore new bulging or double vision
• Do not assume it will go away without medical evaluation

When to See a Doctor

You should see an eye doctor if you notice any change in how your eye looks or feels. The main warning signs are bulging of the eye, double vision, pain with eye movement, or a new feeling of pressure behind the eye.

Blurry vision or loss of side vision is more serious. These symptoms suggest the cyst may be pressing on the optic nerve. The optic nerve connects your eye to your brain. Pressure on it can cause permanent vision loss if not treated.

Headaches that are always on one side, especially around the eye or forehead, can be a sign of a sinus mucocele. If you have a history of sinus problems and develop these symptoms, mention it to your doctor.

Even if you have no symptoms, a cyst found by accident should be followed. Your doctor will tell you how often to repeat imaging. Most people with small, asymptomatic cysts just need a checkup once a year.