The ciliospinal center is a structure which receives input from the pretectum

Pretectum

The pretectum, also known as the pretectal area, is a region of neurons found between the thalamus and midbrain. It receives binocular sensory input from retinal ganglion cells of the eyes, and is the region responsible for maintaining the pupillary light reflex.-Outputs:The pretectum, after...

, and has output to the superior cervical ganglion

Superior cervical ganglion

The superior cervical ganglion , the largest of the cervical ganglia, is placed opposite the second and third cervical vertebræ. It contains neurons that supply sympathetic innervation to the face....

.

It is located in the intermediolateral cell columns of the spinal cord between C8 and T2.

It plays a role in the control of the iris dilator muscle

Iris dilator muscle

The iris dilator muscle , is a smooth muscle of the eye, running radially in the iris and therefore fit as a dilator. It has its origin from the anterior epithelium. It is innervated by the sympathetic system, which acts by releasing noradrenaline, which acts on α1-receptors...

. It is also known as "Budge's center", or "centre".

It is associated with a reflex identified by Augustus Volney Waller

Augustus Volney Waller

Augustus Volney Waller FRS was a British neurophysiologist. He was the first to describe the degeneration of severed nerve fibers, now known as Wallerian degeneration.-Life:...

and Julius Ludwig Budge in 1852.