he science of diagnosis using your iris is called ‘iridology’.

Information that may be obtained:
.the health of your digestion & metabolism of  wastes   
.how you manage your blood sugar 
.the efficiency of your circulation, respiration, hormones & acid levels
.how you cope with stress 
.an analysis of genetic strengths and weaknesses
.Early indications of a condition are often apparent in the eye, before they manifest as symptoms in the body.