What can i do to get rid of these white rings around my iris?

Arcus senilis: If it at the edge of the cornea where it joins the sclera (the white part of the eye), then you are likely referring to arcus senilis. This is a benign condition and you can not really get rid of it. You may want to have your cholesterol checked. It can be (but isn't always) elevated in patients with this eye finding.

Arcus senilis: I presume you are referring to a whitish grey ring in the cornea that appears all the way around the colored part of the eye. Most commonly this is not due to cholesterol. It is a normal finding in people as the age, called arcus senilis. It can be a sign of elevated cholesterol in people younger than 45. It is more visible/noticeable in individuals with dark coloring of the eye.