so the squid can see it's prey and predators and other objects
it is part of the Squids eye Sight...
Optic nerve and ophthalmic artery passes through this foramen to your eye ball.
The optic nerve is a group of nerve fibers that function to provide vision. The optical never works by transferring electrical impulses to the brain from a part of the eyes known as the retina.
The cranial nerves that have some function in vision include the optic nerve (II), which is responsible for carrying visual information from the eye to the brain, and the oculomotor nerve (III), which controls the movement of the eye muscles.
Occipital nerve. It is the second cranial nerve.
As with all nerves in the human body, the optic nerve transmits information. In this case, the optic nerve specifically transmits information from the retina of the eye to the brain for analysis and integration, resulting in the perception of "sight."
Optic disc:The optic disc is also called the blind spot. There are no receptors in this part of the retina. This is where all of the axons of the ganglion cells(last neurons before optic nerve) exit the retina to form the optic nerve.
It is not a function, it is where the optic nerve connect from the eye to the brain. Because of this there are no photo-receptors at that point.
That should be the shutter.
Point where optic nerve enters eyeball is the optic disc.
The optic nerve exits the retina at the optic disc, otherwise known as the "blind spot".
Another name for the optic nerve head is the optic disc.