<s>[INST] My 5 year old son has a red lump on his eyeball. It looks like part of a vein sort of, but it is raised and red. It has been this way for months, maybe a year. I have just never examined closely. He never complains about it hurting or itching or anything.  What could this be? [/INST] Thanks for your question on Chat Doctor. I can understand your concern. Following are the possible causes for eyeball swelling in child Chat Doctor.  1. Hemangioma2. Hematoma 3. Retinoblastoma 4. Keratin nodule etc. Amongst all these, Retinoblastoma is malignant and so better to consult ophthalmologist and get done clinical examination and if needed biopsy of the lesion to confirm the diagnosis. Hope I have solved your query. I will be happy to help you further. Wishing good health to your child. Thanks. </s>