The neurons that cause your eyes to blink are primarily the motor neurons of the orbicularis oculi muscle, located in the facial nerve nucleus. These neurons control the closure of the eyelid by activating the orbicularis oculi muscle. Additionally, the levator palpebrae motor neurons in the oculomotor nerve nucleus are involved in reopening the eyelid after a blink. Specifically, the blink motor control circuit involves:

• Sensory input from the trigeminal nerve (ophthalmic division) detecting stimuli on the cornea or eyelid.
• Sensory signals sent to the trigeminal spinal nucleus.
• Motor output through the facial nerve (cranial nerve VII) to the orbicularis oculi muscle to close the eyelid.
• Motor neurons in the oculomotor nerve (cranial nerve III) controlling the levator palpebrae muscle to open the eyelid again.

This reflexive blink pathway ensures rapid and coordinated eyelid closure in response to stimuli, protecting the eye. Spontaneous and voluntary blinks involve additional brain regions and cortical control but still converge on the orbicularis oculi and levator palpebrae motor neurons for execution.