The feeling of blinking out and suddenly being "back" is far from exclusive to comas or general anesthesia; it has been replicated via deep meditation. Specifically, it seems to be the core feature of what's technically known as nirodha samapatti (lit. "attainment of ceasing").

An easy way of intuiting what it might feel like (if imperfectly, of course) is just keeping a high state of lucidity and mental focus whilst you're naturally drifting in and out of light sleep; this might seem challenging at first but it's actually quite doable.