Tumors can grow within and behind the iris (the colored portion of the eye that controls the amount of light entering the eye). Though many iris tumors are cysts or a nevus, malignant melanomas can occur in this area. Most pigmented iris tumors do not grow. They are photographed and monitored with a special slit lamp and high frequency ultrasound to establish a baseline for future comparisons. When an iris tumor is documented to grow, treatment is recommended. Most small iris melanomas can be surgically removed. Radiation plaque therapy or enucleation may be considered for larger iris tumors.