There's a lot of options with these layered eyes, change the values in the scrolling texture section, change the opacity and you can cover the whole eye.
It's a Kaleidoscope effect, that works with whatever eye you are currently wearing.
Remember, this is 2 tone, so you will have to change the settings for each material, but this way gives way more options, have it only on one, scrolling inwards and outwards at once, different speeds, Lots of combinations :)