Eye cancer occurs when cells in or around the eye undergo abnormal genetic changes and begin to grow uncontrollably, forming a malignant tumour. It is an uncommon group of cancers overall, but an important one to understand well, because the eye's specific anatomy means that even a small tumour can threaten both vision and, in some cases, life — and because several of its most common forms behave very differently from one another.
Eye cancer can be primary, meaning it starts within the eye itself, or secondary, meaning it has spread (metastasised) to the eye from a cancer elsewhere in the body, most often the breast or lung. Among primary eye cancers, uveal melanoma is the most common in adults, while retinoblastoma is the most common in children. Cancers can also arise from the eyelids and the conjunctiva (the clear membrane covering the white of the eye), which behave more like skin cancers and are managed somewhat differently from cancers arising inside the eyeball itself.
The eye is made up of three main layers, and the type of eye cancer that can develop is closely tied to which layer or structure is affected:
Uveal Melanoma
The most common primary intraocular cancer in adults, arising from pigment-producing cells in the choroid, ciliary body, or iris. Often detected on routine eye examination before it causes any symptoms. Carries a real risk of spreading to the liver, which shapes lifelong surveillance after treatment.
Retinoblastoma
The most common eye cancer in children, typically diagnosed before age 5, arising from immature retinal cells. Can be hereditary (linked to a mutation in the RB1 gene, often bilateral) or sporadic (usually one eye only). Highly treatable when caught early, with survival rates exceeding 95% in high-income healthcare settings.
Intraocular Lymphoma
An uncommon cancer, typically a form of non-Hodgkin lymphoma, that can affect the eye in adults. Often associated with lymphoma of the central nervous system, and can mimic inflammatory eye conditions, sometimes delaying diagnosis.
Eyelid and Conjunctival Cancers
Include basal cell carcinoma (the most common eyelid cancer), squamous cell carcinoma, sebaceous gland carcinoma, and conjunctival melanoma. These behave more like skin cancers, are strongly related to ultraviolet exposure, and are generally treated with surgical excision.
Secondary (Metastatic) Eye Cancer
Cancer that has spread to the eye from elsewhere in the body, most commonly the breast or lung. Metastatic disease to the eye is actually more common than primary intraocular cancer in adults overall, and its presence often indicates that cancer has also spread elsewhere.
For uveal melanoma, size is the single most important factor in deciding how a tumour is treated, since it directly affects both the risk of vision loss and the risk of the cancer spreading. Tumours are broadly classified as small, medium, or large based on their basal diameter (width) and apical height (thickness), using criteria established by major international studies such as the Collaborative Ocular Melanoma Study.
Very small tumors may initially be monitored closely with serial imaging, particularly where there is diagnostic uncertainty, since some small pigmented lesions are benign naevi (moles) rather than melanoma. Treatment is initiated if growth or high-risk features are documented.
For medium-sized tumors, eye-preserving treatment is usually the priority. Plaque brachytherapy (a radioactive disc temporarily stitched to the outer eye wall over the tumour) is the most widely used treatment for tumours in this range, offering survival outcomes equivalent to removing the eye, based on landmark clinical trial evidence.
Larger tumours are more likely to require enucleation (surgical removal of the eye) when preserving useful vision and controlling the tumour is not achievable with eye-sparing treatment, though proton beam therapy is increasingly used as an eye-preserving alternative for select large tumours at specialised centres
Beyond size, genetic testing of tumor tissue — typically obtained via fine-needle aspiration biopsy at the time of treatment — has become an important part of modern uveal melanoma care. Certain chromosomal changes and gene expression profiles are associated with a meaningfully higher risk of the cancer spreading to the liver, the most common site of metastasis. This information does not change the treatment of the eye itself, but it shapes how closely a patient is monitored afterward — patients found to carry a higher-risk genetic profile are typically followed with more frequent liver imaging and blood tests for early detection of metastatic disease, since early treatment of liver metastases improves outcomes.
Retinoblastoma deserves particular attention because its most recognisable sign is easy to miss unless parents know what to look for — and because catching it early makes an enormous difference to both survival and the chance of preserving the eye and useful vision.
The hallmark sign is leukocoria — a white or cloudy reflection in the pupil, instead of the normal red-eye reflex, often first noticed by a parent in a flash photograph, or by a doctor during a routine check-up. Other possible signs include a new squint (strabismus), a change in eye colour, or redness and swelling of the eye without an obvious cause. Any of these findings in a young child warrants prompt ophthalmic assessment.
Roughly a third to a half of retinoblastoma cases are linked to an inherited mutation in the RB1 gene, and these cases are more likely to affect both eyes and to be diagnosed at a younger age. A child diagnosed with hereditary retinoblastoma also carries a lifelong increased risk of certain other cancers later in life, which is why genetic counselling and testing are recommended as part of care — not only for the affected child, but to guide screening for siblings and future children in the family, who may need eye examinations from birth if a hereditary mutation is confirmed or strongly suspected.
Many people with eye cancer, particularly uveal melanoma, have no symptoms at all in the early stages, and the tumour is often found incidentally during a routine eye examination. When symptoms do occur, they typically relate to how the tumour is affecting vision or the physical structure of the eye. Pain is uncommon unless the tumour has grown large enough to affect surrounding tissue or raise pressure within the eye.
Many of these symptoms are far more commonly caused by conditions other than cancer, such as retinal detachment, cataracts, or benign eye lesions. This is precisely why they should not be self-diagnosed at home — a detailed examination by an ophthalmologist is the only reliable way to distinguish between them.
Some risk factors have been identified to increase your risk of Eye Cancer. They include:
