1) When one stays up all night on Christmas Eve, and on Christmas morning, their eyes are blood shot.
2)Peeking at your presents before they're wrapped.
1) You could so tell Sara had Christmas eyes yesterday.
2) Mom: Do you have CE?
kid: What's that?
Mom: Christmas Eyes.
Kid: What's that?
Mom: You peeped at the presents didn't you?
Kid: How'd you know?