When people hear the term 20/20, they generally imagine perfect vision—but that's not quite the case. Having 20/20 vision means that you can stand twenty feet from one of those iconic eye charts topped with the big E and successfully read the fourth line from the bottom without the aid of contacts or glasses. And while we aren't suggesting that this isn't a pretty significant feat—what it means is that you have amazingly normal vision.
If you've ever experienced an eye twitch—or spasm—you know it feels like the whole world can see that your eye is flickering out of control at what feels like the same pace as a hummingbird's wings. Most of the time this quivering sensation is barely noticeable to the people around you, and it ends as quickly as it begins. But, not all eye twitches are the same, and some symptoms need closer attention.