ریدولوژیست ها ادعا می کنند که آنها بیماری های خاص را تشخیص نمی دهند ، بلکه این امر است “برجسته کردن” آن سیستم ها و اندام های بدن که سالم هستند و آنهایی که توصیف می شوند “بی پروا” یا “التهاب” These are said to point to a tendency in the patient towards certain illnesses, to reflect past medical problems, or to predict health problems which may be developing.Since iridology is not a method of treatment, its practitioners have often studied other branches of alternative medicine, such as naturopathy, and used the study of the iris as a diagnostic first step. Iridology is practiced more widely in Europe (especially in the UK and Germany), where there are approximately 20,000 practitioners, than in the United States, which has only a tenth of that number.