I get the twitches too. I think it is from staring. Sometimes, when I am "off in my own little world" I tend to stare. I don't think we blink as much.
But, let me ask you something. Sometimes, it feels like all my nerves are strung thru my body like guitar wires. If there is a noise, like a car starting or something, they twang. It's a really weird, uncomfortable feeling.