It is not fully known why eye cancer develops. You may be more likely to develop certain types of eye cancer if you have blue, grey or green eyes, unusual brown spots on your eye, lots of unusually shaped or large moles(atypical mole syndrome), been out in the sun too much without wearing sun protection such as sunglasses or a wide-brimmed hat, a weakened immune system-people who have HIV/AIDS, or who are taking medicines that suppress the immune system, are more likely to develop lymphoma of the eye, inherited genes such as the faulty retinoblastoma gene.
Attribution: BUPA