Choroidal melanoma is a cancer of the eye that develops in a part of the eye called the choroid, the spongelike membrane that lies between the sclera (the white of the eye) and the retina. The choroid is rich in blood vessels and supplies nutrients to the retina, the light-sensitive back of the eye that sends visual information to the brain. Although choroidal melanoma is a rare form of cancer, it is the most common cancer that develops in the eye in adults.
This cancer often doesn’t cause any symptoms in its early stages, so the tumor may grow for some time before the problem becomes noticeable. When symptoms occur, they include blurred vision, floaters, flashing lights, or severe eye pain. These symptoms also can be caused by many other, more common, noncancerous causes.