What does the ring around the iris mean?

Ring around iris.: Most likely the "ring" in in the cornea and represents a deposition of lipid which is very common as we get older, it has been named " arcus senilis". However there are other pathological states principally affecting the liver that may cause such ring, example being the keyser-fleisher ring, a deposition of copper in the cornea. It is commonly seen in wilson's disease and obstructive liver disease.

Corneal arcus: This is a deposit of lipid from the blood circulation near the outer edge of the cornea. It is not on the iris although it looks as if it might be on the iris when viewed in a mirror. It used to be though there was a relationship between this and blood cholesterol, but studies have shown this is not true.