Classic iridology points to adrenal function in relation to pupil dilation.
Metals can interfere with adrenals.
If you are exhibiting signs of stress or fatigue you can provide support to the kidney's/adrenals with B & C Vitamins. Also look into using Cordyceps mushrooms both extract and whole.
If the adrenals are feeling sore to the touch then look into using castor oil packs.