Causes

It's not clear what causes eye melanoma.

Doctors know that eye melanoma occurs when errors develop in the DNA of healthy eye cells. The DNA errors tell the cells to grow and multiply out of control, so the mutated cells go on living when they would normally die. The mutated cells accumulate in the eye and form an eye melanoma.

Where eye melanoma occurs

Eye melanoma most commonly develops in the cells of the middle layer of your eye (uvea). The uvea has three parts and each can be affected by eye melanoma:

• The iris, which is the colored part in the front of the eye
• The choroid layer, which is the layer of blood vessels and connective tissue between the sclera and the retina at the back of the uvea
• The ciliary body, which is in the front of the uvea and secretes the transparent liquid (aqueous humor) into the eye.

Eye melanoma can also occur on the outermost layer on the front of the eye (conjunctiva), in the socket that surrounds the eyeball and on the eyelid, though these types of eye melanoma are very rare.