My theory is that this darting is the mechanism of consciousness. We look inward and outward in a loop, which generates the perception of being conscious in a similar way to how sequential frames of film create the illusion of motion. That "persistence of vision" is like the illusion of persistent, continuous consciousness created by the inward-outward regard sequence. Consciousness is a simple algorithm: look at the world, then look at the self to evaluate its reaction to the world. Then repeat.