Uveal melanoma is a type of eye cancer in the uvea of the eye. It is traditionally classed as originating in the iris, choroid, and ciliary body, but can also be divided into class I (low metastatic risk) and class II (high metastatic risk). Symptoms include blurred vision, loss of vision or photopsia, but there may be no symptoms. Tumors arise from the pigment cells that reside within the uvea and give color to the eye. These melanocytes are distinct from the retinal pigment epithelium cells underlying the retina that do not form melanomas. When eye melanoma is spread to distant parts of the body, the five-year survival rate is about 15%. It is the most common type of primary eye cancer. Males and females are affected equally. More than 50% spread, mostly to the liver.

Reference
Wiki: Intraocular melanoma