If you’re one of the 5-10% of people who have brown spots on your eyes, you’re probably wondering what they are and what causes them. There are several possible reasons for these spots, the most common being choroidal nevus, more commonly known as eye freckles and are usually as harmless as they sound.
Just like freckles on your skin, eye freckles are caused by a build-up of melanin or pigment. The pigment cells cluster together forming spots which are often not visible to the naked eye, varying in size and shape. You may not even know you have them unless they are pointed out to you during your eye exam. Although they can be present at birth, eye freckles usually appear later on, at the same time as skin freckles or later on in life. The freckles can appear in the white part of your eye – the sclera – or in the iris – the coloured part. They are particularly difficult to spot when located in the iris as they can range in colour from grey to black or brown.
Primary acquired melanosis
If eye freckles are noticed during your eye exam and they newly appeared or are thought to be suspicious, they may be examined more closely or kept under observation, especially if the freckle is raised, orange in colour or leaking fluid. Photography is typically used to keep track of the size of the freckle. Only around one in 20,000 eye freckles will turn out to be cancerous, making this an extremely rare occurrence.
Some medicines such as epinephrine can cause darker spots on the white part of your eye. Endocrine diseases and hormonal changes might also make this area darker.
Axenfeld nerve loop
These are loops of nerves behind the white part of your eye. You may be able to see them in the eye as greyish shapes.
Any small objects can become lodged in your eye, for example, specks of wood, metal or insects. Damage can be caused to your eye if these are removed improperly, so always seek medical attention.
When to consult a doctor
Brown spots on the eye are not usually dangerous, but if you have them, it’s a good idea to have an eye exam at least every year. They do not usually require any treatment, being harmless and it is not possible to remove them safely for cosmetic purposes. In the rare cases where eye freckles are found to be cancerous, laser eye surgery, radiation therapy or a combination of the two may be used.