Excerpt from Michael Caine’s awesome book Michael Caine – Acting in Film: An Actor’s Take on Movie Making 
I don’t blink. Blinking makes your character seem weak. Try it yourself: say the same line twice, first blinking and then not blinking. I practiced not blinking to excess when I first made this discovery, went around not blinking all the time and probably disconcerted a lot of people. But by not blinking you will appear strong on screen. Remember: on film that eye can be eight feet across.
Blinking is one of my favorite gestures because it says so much about who you are. Think of; The Quick, flutter, or The Slow Blink. When I think of The Blink and how it’s used. I think of Leonardo DeCaprio in “What’s Eating Gilbert Grape” (The Flutter. Says vloumes about who he is), Streep in “Sophie’s Choice” (not a movement in her eyes), and Bette Davis in “What Ever Happened To Baby Jane”, (Davis uses the blink in certain scenes only when she’s drunk. )
Not blinking hurts! I’ve practiced for the past 2 hours and yes, it hurts! It doesn’t matter at this point if I seem weaker. Now, I couldn’t see Michael Caine blinking during his deliveries, that’s how I like him :-)
Now, have you seen Mark Zuckberger from Facebook? That’s disconcerting :-0