Uveal melanoma is the most common type of eye cancer, and it affects any of the three parts of the uvea; the iris, ciliary body or choroid. The typical uveal tumor is an elevated mass that can either be dark brown in color or amelanotic. Conjunctival melanoma occurs when a tumor grows in the outside lining of the eyeball, and it mostly looks like a black spot. Intraocular melanoma can spread quickly to other parts of the body if not treated early enough. However, this kind of eye cancer is not hard to diagnose and treat because the symptoms and the spots are relatively visible early on.