The eye is made up of three layers of specialized tissue. The cornea and sclera form the fibrous tunic; the choroid, ciliary body, pigmented epithelium, and iris form the uvea; and the retina is on the posterior part of the eye. The parts surrounding the eye are called adnexal structures, and they form the eyelids, conjunctiva (mucous membrane that lines the inside of the eye lid), and lacrimal glands. There are as many types of cancer that can grow out of the eye structures as there are tissue types.
Information taken from Canadian Cancer Society.