OMG. You don't know ZeFrank? I get the feeling you'll love him. Check this out: https://www.youtube.com/watch?v=v-s714RNXHY

And while the video above explains how eye spots appear, it doesn't explain the most commonly accepted reason why they appear - self defense. Consider the size of the eye spots on a moth's wings as compared to the size of its actual eyes. The eye spots make it look much bigger than it actually is, so that it's less likely to get eaten.