Although the optic nerve uses the optic canal, there are other nerves that serve the eye. They control the eye muscles and deliver the messages that focus and control
light (iris size) etc. They are:
frontal (which branches to supra orbital & supra trochlear), &
The frontal, lacrimal, and
nasociliary skim off the top of the trigeminal nerve as the rest of it divides toward other exits.