What causes a white ring around the iris?

A fellow caregiver asked...

What could be causing a white ring on the top of my iris?

Expert Answer

Lylas Mogk, M.D. is an ophthalmologist and director of the Henry Ford Visual Rehabilitation and Research Center in Grosse Pointe and Livonia, Michigan, and the author of Macular Degeneration: The Complete Guide to Saving and Maximizing Your Sight.

The white ring you see on top of your iris is most likely a deposit of cholesterol around the edge of your cornea, the clear dome that covers the iris. This cholesterol deposit is known officially as a pinguicula. If you are young, this could suggest high cholesterol; if you are a senior citizen, it may not, as it is fairly common in older people and not necessarily suggestive of high cholesterol. The white ring stays around the edges, like a halo, and does not cause damage to your eye or your vision.