Eyes are asymmetrical.
It's cos I had the other half of the drawing covered up while I was working on it. I mean, I had a full pencil drawing underneath as a guide for both sides, but that doesn't completely compensate for not being able to see the other half of the drawing, you know, unless you're following the lines 100% and your lines were perfect to begin with.
In fact, the jawline isn't entirely symmetrical either, it's just that mistakes w/ the eyes are far far more recognizable since (I'm guessing) humans get so good at reading emotion from eyes and therefore noticing minute changes in the eyes.
But ya, adding the left eyebrow helped, it's just the left iris and retina being slightly off center or at least asymmetrical to the right one that's bothering me. But oh well, the drawing is fixed now so there's nothing really I can do to it.
