Cancer of the eye. Tumour of the conjunctiva, the clear membrane that coats the eye and the interior of the eyelids. This is a squamous cell carcinoma, a type of cancer caused by proliferation of surface epithelial cells. The tumour (pink) is partially obscuring the eyeball. This type of tumour grows slowly and rarely metastasizes to other regions of the body. Diagnosis is by tissue biopsy and treatment is by surgical excision, radiotherapy, chemotherapy or cryotherapy.