My eyes haven't cycled for the longest time - no big emotional swings to the emotions that trigger them. My eyes were weird what I was in my teens, different people saw all three colours, most of them saw the default combination.
Under normal circumstances, my eyes are coloured in 3 rings, from outward in the pupil: smooth and thin blue ring , broad rounded cell green ring, crackly thin yellow ring.
Each color became more dominant as each of these three emotions became dominant (respectively): Love/lust, playful/mischievous, and anger.
Various girlfriends saw the first two on different occasions, but the last one had two landmark moments that ended up freaking out the people who witnessed it. Once was standing with my then-mother-in-law in a speech to run a terrible person out of her father's house, to protect him from her money-draining and abusive ways. The other was over some bad news I received concerning my first wife, and I had to meet a friend not an hour after getting the news - they asked if I was ok before anything else.
They haven't changed in a long while, like I said, but knowing they have makes me stand out even more. (Like I need to...)