If for whatever reason you have to turn off the eye tracking part of the tracker, the eyes lock in their current position. I like this because it allows you to control how wide they are when you lock them.

However, locking into a fixed position looks unnatural for obvious reasons. If this "locked state" instead were the position the eyes were at 95% of the time and the rest of the time the eyes automatically transitioned from there to closed and back again, blinking could exist for all users regardless of eye tracking.

Note: I have eye tracking disabled because I wear sunglasses, not due to eye tracking bugs. With all bugs eliminated, this would still be a helpful feature to some. (: