Tell you the scientific reasoning behind eye twitching and blinking?

Answer 1

The orbicularis oculi muscle allows us to blink or close our eyes. Twitching involves involuntary control of the eyelid muscles, while blinking involves voluntary control of the eyelid muscle.

Answer 2

To keep your eyeball moisturized, every blink spreads a tiny ammount of tiers over the eye ball. If you would not blink you would become irreversably blind in less than a day.