This is where radiation from a machine is targeted at cancer cells from outside the body. We find this treatment useful in patients that have cancer else where in the body that has spread to the back of the eye. On the other hand, if there has been a large tumour inside the eye that has grown behind the eye, we may choose to use radiotherapy after removing the eye. This treatment is spit into fractions. This means the treatment is divided into smaller doses and spread out over a few days. This gives healthy cells in the body a chance to recover between treatments. If we are using radiation to treat the eyes or lymph nodes around the head and neck, then a special mask is usually made for patients. This mask is worn during treatment and helps aim the radiation at only the cancer cells. Although this helps prevent damage to healthy cells around the tumour, treatment may still cause loss of eyelashes, loss of pigmentation of the eyelids, and inflammation of the conjunctiva causing a watery eye.