eye design 4 detail

If I were to ever be stared at by the eyes of an angry or serious dragon or being, I would not be surprise if his expression resembled this terror. I also would not be shocked to find someone having this as a tattoo. I myself consider this art work on my arm or even my own neck.
At a first glance, the grooves and lines look chaotic, but when studied closely any one can tell there's a pattern. I wonder if you used a pencil sketch before inking this in, or a plan? Without either, one is prone to make mistakes, but I do not see any.
This might be a poster someday.