context: A retinoblastoma is a cancerous tumor on a part of your child's eye called the retina. It sounds scary, but it's highly curable if you catch it early. Your child's eyes begin to develop very early in the uterus. Cells called retinoblasts grow until they form her retina. This is the part in the back of her eye that senses light. Sometimes something goes wrong. The cells don't stop growing and a tumor forms on her retina. The tumor may grow until it fills the inside of her eyeball. Cancer cells can break off and spread to other parts of her body. Mostly children 5 years old and under. It rarely affects adults. Between 200 and 300 children are diagnosed each year. A little less than half of all cases are inherited. That means the gene that makes the cells grow is passed from parent to child. Most of the time retinoblastomas only affect one eye. Inherited cases are more likely to affect both eyes. You might notice: Her pupils look white -- not red -- when you take pictures of her. Blood vessels in the back of her eye should reflect red. If they don't, there could be a tumor. Her eyes don't move or focus in the same direction. She acts like her eyes hurt. Her pupils are always wide open. One or both eyes are often red. Her doctor will check her eyes. If he sees some of the signs noted above, he might order an imaging test to look for tumors. If he thinks she has a retinoblastoma, he'll tell you to take her to an ophthalmologist -- a doctor who treats eyes. That doctor will use special equipment to look at her retina. She may do tests to figure out the stage of the tumor, or how far it has spread. These tests include ultrasound, MRI scans, CT scans, bone scans, a spinal tap, and bone marrow tests. They include: Intraocular retinoblastoma. The earliest stage, found in one or both eyes. It hasn't spread to tissue outside the eye. Extraocular retinoblastoma. The cancer has moved outside of her eye to other body parts of her body. Recurrent retinoblastoma. The cancer has returned. It could be in the eye or in other parts of the body. Because it's usually found before it spreads outside of the white of the eye, this cancer is highly curable. Many types of treatment can save your child's sight. Your doctor will choose treatments based on the stage of cancer at the time of diagnosis. Options include: Photocoagulation. A laser kills blood vessels that feed the tumor. Cryotherapy. Extremely low temperatures kill cancer cells. Chemotherapy . This medicine helps to kill or slow the growth of cancer cells. Your child may get it in a few ways: Injected into a vein (the doctor will call this intravenous) As a pill Injected into the fluid that surrounds her brain and spinal cord (called intrathecal chemotherapy) Radiation therapy . It can be given two ways: from inside her body (internal) or outside (external). External-beam radiation therapy uses X-rays to kill cancer cells. In internal, or local radiation therapy, the doctor places small amounts of radioactive material inside of or near the tumor to kill cancer cells. Surgery. The doctor surgically removes her eye. Over 90% of children will live more than 5 years after being diagnosed with retinoblastoma. How much eyesight they have depends on how severe the disease was, as well as the treatment they received. Inherited forms of retinoblastoma are more likely to come back years after treatment. Children who have had it need close follow-up after treatment. Because genetics and age play such large roles in this condition, the best prevention is through finding it early. All babies should have a general eye exam at birth and then again during the first year of life. ( These are usually included during the "well-child" visits scheduled at 2, 4, 6, 9, and 12 months.) Your child should also have regular exams scheduled for 15, 18, and 24 months of age and every year after that. At these visits, her doctor can spot any serious problems and check for the retinal tumors. Newborns with a family history of retinoblastoma should have a more thorough eye exam at birth, again at several weeks of age, and then once every few months as directed by the doctor. Note: If you notice something unusual about your child's eyes in between the regular visits, contact your doctor for an appointment immediately. If your family has a history of retininoblastoma, a blood DNA test can look for the gene mutation that causes it. Adults should get a thorough regular eye exam at least once a year. Go more often if you have a personal or family history of eye disorders or diabetes.