Today I posted an image on Instagram of an iris with variation in colour as well as a few dark spots that looked like freckles. As I manage a lot of eyelid skin cancers and other lumps and bumps I am always on the look out for anything sinister. Your iris is the coloured part of your eye and like any other part of your eye that has pigment, some of those cells can change and cause cancer.
The good news is that iris freckles (naevi) are relatively common and transformation to cancer is very rare. The other piece of good news is that even if an iris freckle does transform to a cancer, it is far less likely to metastasise or travel to other parts of your body compared to other cancers. This is good because it means we can monitor such lesions with photographs to see if they are changing over time.
Things to look out for are rapid changes in size of a freckle or distortion of the shape of the pupil. Other more subtle changes need to be looked for under the microscope with your optometrist or ophthalmologist. If you do have any concerns or have any iris freckles that you think may be worth having a baseline check of, you can contact an eye care professional. It is always good to have a good quality baseline photo to compare to if there are any future concerns.
It would be very unusual to need to biopsy an iris freckle unless there are significant concerns that it has transformed. So don't worry, a trip to get your iris photographed is not going to mean going to have a biopsy taken as can happen with some skin lumps and bumps.
The other interesting feature of the photo of todays iris was the variation in colour. It is quite rare but eyes can be different colours in the same person and even the same iris can have sector variation. This iris had a central variation of brown near the pupil and blue near the limbus. This is a benign condition.
So my tip for today is that if you notice any pigmented area on your eyes anywhere, including the iris, it is good to get it checked and photographed. Just like you would take care of your skin and get a mole map. Ther other important point is UV protection from the sun with sunglasses. Most iris melanomas occur inferiorly where they receive more UV exposure so blocking UV light reduces your chances of trouble in the future - as a bonus it keeps you looking younger too.