Mine was the entire eyeball, but it was mostly directly behind my eye.

Closest description I can use, imagine root canal pain, but directly behind your eyeball. (root canal pain is nerve pain too. I thought optic nerve pain was worse tho)

It's very painful, especially when you move your eye side to side, but can also hurt at any movement of your eye, or be a constant pain. You dont realize how often you move your eye until you get pain in your optic nerve. (you pretty much move your eyes constantly, even when you think you're not moving your eyes)