Eye melanoma most commonly develops in the cells of the middle layer of the 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.