Why does my eye keep twitching?

So, my eye kept twitching today, and i am so annoyed. like it was non stop. and i know it isn't rest deprivation because its summer, and i am sleeping in til like noon! i mean yeah, i have been drinking some coke-a-cola a lot, but does that make a difference? i am scared, and no a doctor cant really determine it, because i am not able to see one at the time. thanks!