ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Eye Cancer. To see other pages, use the menu on the side of your screen. Think of that menu as a roadmap to this full guide.
Eye cancer is a general term used to describe many types of tumors that can start in various parts of the eye. It occurs when healthy cells in or around the eye change and grow uncontrollably, forming a mass called a tumor. A tumor can be benign or cancerous. A benign tumor means the tumor can grow but will not spread. A cancerous tumor is malignant, meaning it can grow and spread to other parts of the body. Cancer that forms in the eyeball is called an intraocular (inside the eye) malignancy.
Medical doctors who specialize in the diseases and function of the eye are called ophthalmologists or “eye MDs”. These doctors can diagnose and treat intraocular melanoma (see below). Optometrists are another type of eye doctor. They prescribe eyeglasses and contact lenses. They are not medical doctors and are not trained to treat intraocular cancer.
Parts of the eye
The eye is the organ that collects light and sends messages to the brain to form a picture. The three main parts of the eye are:
Orbit (eye socket)
Adnexal (accessory) structures, such as the eyelid and tear glands
The outer part of the eye is made up of the sclera, retina, and uvea. The sclera is the outer wall of the eyeball. The retina is a thin-layered structure that lines the eyeball and sends information from the eye to the brain. The uvea nourishes the eye. Both the retina and the uvea contain blood vessels.
The uvea consists of the following:
Iris: The colored part of the eye that controls the amount of light entering the eye
Ciliary body: Muscular tissue that produces the watery fluid in the eye and helps the eye focus
Choroid: The layer of tissue underneath the retina that contains connective tissue and melanocytes, which are pigmented (colored) cells, and nourishes the inside of the eye. The choroid is the most common site for a tumor.
Types of intraocular cancer
The most common intraocular cancer in adults is uveal metastases, which is cancer that has spread to the uvea from another place in the body. This is called secondary cancer. This guide is about primary intraocular cancer, meaning that the tumor started in the eye, not somewhere else in the body.
Melanoma  is the most common type of primary intraocular cancer in adults. It begins when cells called melanocytes grow uncontrollably. Intraocular melanoma is also called uveal melanoma.
Other, less common types of an intraocular tumor include:
Intraocular lymphoma is lymphoma that begins in the eyeball. This condition is rare and can be difficult for doctors to diagnose. Many doctors consider intraocular lymphoma to be a type of central nervous system lymphoma. Most intraocular lymphomas are non-Hodgkin lymphoma .
Retinoblastoma  is a rare form of childhood eye cancer.
Hemangioma is a benign tumor of the choroid and retina that starts in the blood vessels.
Other, rare cancers of the eye include:
Conjunctival melanoma is a tumor of the conjunctiva, which is a membrane that lines the eyelid and eyeball. If it is not treated, it can spread to the lymph nodes, which are tiny, bean-shaped organs located throughout the body that fight disease. A conjunctival melanoma tends to recur (come back after treatment) on the eye’s surface and looks like dark spots on the eye. Doctors often perform a biopsy on a spot that appears to be conjunctival melanoma. A biopsy is the removal of a sample of the tissue for examination under a microscope.
Eyelid carcinoma  (basal or squamous cell) is a variation of skin cancer. This tumor may be surgically removed and is usually not dangerous if it is treated early.
Lacrimal gland tumor  is a benign or malignant tumor of the glands that produce tears.
The next section in this guide is Statistics  and it helps explain how many people are diagnosed with primary intraocular cancer and general survival rates. Or, use the menu on the side of your screen to choose another section to continue reading this guide.