Ciliary Body

The ciliary body, behind your iris, is one of a group of eye parts that make up your uvea. The ciliary body’s jobs include making aqueous fluid and controlling the muscle that lets your lens change shape to focus on what you’re seeing.


What is the ciliary body of the eye?

The ciliary body is located behind the iris of your eye. Your iris is the colored part of each of your eyes. Your iris has muscles that control your pupil.

The iris, the ciliary body and the choroid are connected and make up an area of your eye called the uvea. The choroid is a network of blood vessels and is located at the back of your eye in between your sclera (the white part of your eye) and retina.


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What does the ciliary body of the eye do?

The ciliary body has two main jobs: To make aqueous fluid and to change the shape of your lens while your eye is focusing.

The aqueous fluid, also called aqueous humor, is clear and takes up the space between your cornea and iris. It provides pressurization to your eye the way air fills a ball. It also brings nutrients to your lens and cornea. Your cornea is a layer of protection for your eye.

The ciliary body contains muscles that make your lens change its shape while you’re focusing on what you’re seeing. When you’re looking at something closer, your lens becomes rounded. When you’re looking at something farther away, your lens flattens out. This happens because of the zonular fibers that stretch from the ciliary body to support your lens.

Many researchers believe that ciliary body function is related to presbyopia. This is the word for why people older than 40 have a difficult time focusing on objects that are near.


Where is the ciliary body located?

The ciliary body is a component of the uvea in your eye. Your uvea contains your iris (the colored part of your eye), along with the ciliary body and choroid. The iris, ciliary body and choroid flow into each other like one curved street that changes names a few times. Along with the name change, the function of the tissue changes.

Your iris controls the movement of your pupil and how much light gets in your eye. The ciliary body connects on each side of your iris to control the movement of your lens. Your lens and cornea work together to get light to the right spot on your retina.

Your eye care provider may use eye drops that paralyze the ciliary body in order to test you for refractive errors (nearsightedness or farsightedness).

The choroid is a network of blood vessels located between your retina and sclera (the white part of your eye). The choroid’s blood vessels provide nourishment to the photoreceptors in your retina. The photoreceptors are the cells that change light into electrical signals. The signals go on to your brain through your optic nerve and become images.


What does the ciliary body look like?

You can’t see the ciliary body because it’s behind your iris. The ciliary body is shaped like a ring. It has pleats or ridges that flare out called ciliary processes. These ciliary processes secrete aqueous fluid and point toward your iris. The ciliary body’s zonular fibers provide support to the lens in your eye.

What color is the ciliary body of the eye?

The ciliary body’s external epithelium, or protective layer of tissue, is dark in color. The inside layer is clear.


Conditions and Disorders

What are the common conditions and disorders that affect the ciliary body of the eye?

There are several conditions that can affect the ciliary body of the eye. These include inflammation and infections, tumors and masses, along with other diseases. Severe infections can cause inflammation and then cause the ciliary body to shut down.

Inflammation and infections

Uveitis” is a term for inflammation and possible infection of your uvea. This can affect the ciliary body, as the ciliary body is one of the parts of your uvea. Untreated uveitis can lead to vision loss.

Another type is iridocyclitis, which is inflammation that affects your iris and the ciliary body. It may be caused by an infection or by another condition like arthritis, or it may not have a known cause. Many cases resolve after a brief time, but some can affect your vision permanently.

Tumors and masses

Tumors, masses and cysts can all affect your eyes, including the ciliary body. There are adenomas or small noncancerous tumors that have the potential to become cancerous.

Intraocular melanoma is cancerous and commonly starts in your uvea, often in the choroid. Intraocular melanoma is the most common type of eye cancer in adults, but still happens rarely. It can progress into the ciliary body.

Cysts can form anywhere in your body. Cysts on the ciliary body may lead to repeated cases of inflammation that can cause uveitis.

Other conditions

The ciliary body can be damaged and diseased from many other factors. Some of them include:

  • Optic atrophy: This condition, which involves damage to your optic nerve, may indicate that there’s something else happening with your eye.
  • Glaucoma: Backed-up aqueous fluid causes high eye pressure in glaucoma. The ciliary body is responsible for producing this fluid.
  • Eye injuries: Blunt trauma like those that happen in car accidents or are caused by fire or chemicals can cause ciliary body detachment.
  • Coloboma: This term refers to an area of missing tissue in your eye. Colobomas are present at birth.

What are some common signs or symptoms of conditions of the ciliary body of the eye?

If you have a medical condition that’s affecting the ciliary body, you may notice these signs and symptoms:

What tests may be used to check on the health of the ciliary body of the eye?

Your eye care specialist will begin with a comprehensive eye exam and ask you about your medical history and your symptoms.

If your provider suspects you have any condition affecting the ciliary body, they may suggest one or more of the following tests:

  • Ultrasound biomicroscopy: This is a high-resolution test using sound waves to provide an image of your eye and its parts.
  • Optical coherence tomography (OCT): This test is noninvasive and uses reflected light to provide images of the back of your eye.
  • Angiography: This type of test uses dyes to show the blood vessels in your eye.
  • Biopsy:This test checks for cancer by removing tissue and examining it under a microscope.

What are the treatments for conditions that affect the ciliary body of the eye?

Treatments for eye conditions depend on what type of condition you have. Therapies may include:

  • Medications, given as lotions, eye drops, tablets or injections.
  • Procedures using lasers or extreme cold (cryotherapy).
  • Surgical procedures, which may remove things from the eyes or add things (like lenses to treat cataracts).


How can I take care of the ciliary body of my eye?

Here are some tips for taking care of your eyes:

  • See your eye care specialist for regular eye exams. Keep track of any symptoms and discuss them with your provider.
  • Make sure your lighting is adequate so your eyes don’t have to strain.
  • Eat a healthy diet that contains plenty of the nutrients that your eyes need, like vitamins A, C and E. These are found in fruits and vegetables and other healthy foods like oily fish. You may want to ask your provider about taking vitamin supplements if you know your diet may not be meeting your needs.
  • Exercise regularly.
  • Stay hydrated by drinking water.
  • Limit alcohol and caffeine intake.
  • Quit smoking.
  • Wear sunglasses to protect your eyes. Wear protective glasses if you need them for work or sports.

A note from Cleveland Clinic

Eyes are intricate organs, and every component has a vital part to play — like the ciliary body, which makes aqueous fluid, which nourishes your lens and cornea. Although you can’t prevent every medical condition, you can help by doing your best to stay healthy. What keeps your body healthy keeps your eyes healthy, like eating a nutritious diet, getting adequate exercise and hydration, and not smoking. It’s also smart to have an eye care provider that you see regularly and to keep track of any change in your vision.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 03/17/2023.

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