An ocular nevus, commonly referred to as an “eye mole” or “eye freckle,” is a pigmented spot found on or within the eye. These spots are similar to moles on the skin and are typically common and harmless. They form when melanocytes, the cells responsible for producing pigment, cluster together. While most eye moles are benign, they warrant monitoring because, like skin moles, they have a small potential to change over time.
Where Eye Moles Appear
Eye moles can develop in various locations, each with a specific medical term. A conjunctival nevus appears on the conjunctiva, which is the clear film covering the white part of the eyeball. These moles are often visible to the naked eye, varying in color from yellow to brown, and their shading can change over time.
An iris nevus is located on the iris, the colored part of the eye. These are larger than iris freckles and can be brown, yellow, or grayish, sometimes appearing flat or slightly raised. The third type, a choroidal nevus, is found at the back of the eye, beneath the retina, in a layer called the choroid. This type is not visible externally and can only be detected during a comprehensive eye examination by an eye care professional.
Understanding the Risk
While most eye moles are benign, they carry a very small risk of transforming into a type of eye cancer called ocular melanoma. This transformation is rare; only about 1 in 9,000 choroidal nevi per year become melanoma. The risk of an eye mole becoming cancerous is low, but regular monitoring is important because early detection is crucial for successful treatment.
Warning signs that an eye mole might be changing include an increase in the mole’s size, a change in its shape, or a shift in its color, such as turning orange. Other concerning symptoms can involve new visual disturbances like blurred vision, flashes of light, or an increase in floaters, which are small specks or wavy lines in your field of vision. A choroidal nevus that is thicker than 2 millimeters or shows signs of fluid leakage under the retina also raises concern. If the mole is on the iris, a change in pupil shape can also be a sign.
When to See an Eye Doctor
Consult an eye doctor if you notice any new or existing spot in your eye, even if it seems harmless. While many eye moles are benign, they should be monitored by a professional. Regular comprehensive eye exams are important, especially if you have an eye mole.
Seek immediate medical attention if you observe any warning signs of a changing eye mole. These include an increase in the mole’s size, a change in its shape or color, or new visual symptoms such as blurred vision, flashing lights, or an increase in floaters. Prompt evaluation ensures that any concerning changes are addressed quickly.
What to Expect at the Eye Doctor
When you visit an eye doctor for an eye mole, they will conduct a thorough examination to assess its characteristics. This often includes a dilated eye exam, which allows the doctor to view the internal structures of the eye more clearly. For moles at the back of the eye, such as choroidal nevi, the ophthalmologist may use specialized imaging technologies.
These advanced tests can include optical coherence tomography (OCT), which provides detailed cross-sectional images of the retina, and ultrasound of the eye, used to measure the mole’s thickness and size. Photographic imaging is also a standard practice, capturing baseline images to compare against future examinations. For most benign moles, the primary approach is careful monitoring, with follow-up appointments typically scheduled every six months to a year.