I thought I would finally share more on the subject XD
The most noticed change is when your pupil dilates. This causes light to shine off the different layers inside your iris (which are now compacted), causing them to look brighter. This action can happen when the lights are dimmed, when angered, when you feel threatened, or when aroused. Some substances also cause this effect.
When someone gets a toxic buildup in their system, it shows as a sludge or foggy look in the iris. Say a normally healthy person with blue eyes takes drugs for years. This will often show up as a brown(or orange) ring starting from the pupil and moving out towards the outer edge of the iris (known as the ocular aura). This can also happen from issues with digestive health or overuse of medication.
When someone has an organ removed, or a large cut, it will appear as a black mark in the iris until it heals. Obviously if an organ is removed, the black gap will remain for life. Pain and major trauma can show up as white lines, or a white ring all around the iris (known as a sodium ring).
When looking at the iris, the right eye represents the right side of the body, the left represents the left. The top section of they iris correlates with the brain and head. The bottom shows pelvic organs and lower extremities. The outer edges represent the lungs, arms, chest and adjacent organs. The inner part (towards the nose) represents the throat and thyroid. The area all around the pupil represents the digestive organs. The ocular aura is said to show our relationships with ourselves and other people. A faded edge to iris is meant to mean you blend well with others and are more balanced. A bold edge means you stand out and away from others.
One major thing to look out for in your or someone's eyes is a sunburst pattern. When there are dark streaks going straight out of the pupil towards the ocular aura, this is said to mean the person is having major issues. When going through the head zone, it often represents psychosis, severe mental health disorders, or going about their life in a way that is detrimental to their well being.
It is not known why the iris reacts to such small things in the body. It has been proven time and time again, that what goes on within us shows up in our eyes. Many "readers" will even tell you that they can read you best by seeing your eyes.
This is just a little bit of information about iridology. If you are interested in hearing more, let me know. Remember that it is not a perfect science. Sometimes things happen or are seen for unknown reasons.
L. L & B