The short ciliary nerves are small nerves that arise from the ciliary ganglion, located behind the eye. They primarily carry sensory information from the eye and provide autonomic innervation to the iris and ciliary body, which are essential for controlling pupil size and lens shape during focusing. These nerves are crucial for the function of the parasympathetic nervous system, helping regulate eye functions such as accommodation and light reflexes. Damage to the short ciliary nerves can lead to vision problems and issues with pupil response, highlighting their importance in ocular health.