The only effective cataract treatment is surgery to remove the diseased lens. Neither diet nor medications has been shown to stop cataract formation. In a cataract operation, the eye’s natural lens is removed. Vision can then be obtained by implanting a permanent intraocular lens (IOL), which replaces the natural lens. This artificial lens is made of plastic and is usually inserted at the same time the cataract is removed. Depending on the individual case, the lens is placed directly behind or, less frequently, in front of the iris, the “colored” part of the eye.